So here's a random thought, have witches lost their power as villains and monsters in fiction? And by fiction I really am talking fiction as in the stereotypical pointed hat wearing, warty minions of Satan with their familiars, and I'm not about to get murky by bringing realism into it.
Initially witches were up there with werewolves and vampires as things to be feared, they could cast spells, make poisons, summon spirits and they worked for the devil or Hecate or some other deity, and had familiars that could be spying on you. Sometimes they were necromancers and could summon the dead. They were villains, they poisoned people , murdered animals, killed children, fed on children, etc, etc.

Obviously as there were wicked witches, wizards and warlocks in fiction so too were there good ones but this post is focusing on the transformation of the villain witches. For example, the Wicked Witch of the West, as most popularly seen in the 1939 Wizard of Oz movie and the book and musical Wicked, became a stereotype- green faced, pointy nose, ugly, pointed hat. In the book she had three pigtails and one eye and was in alliance with two other wicked witches in an attempt to take over Oz. Her weakness was water and she had flying monkeys for minions. In the book she uses a Golden Cap to control the monkeys, she uses them to enslave the Winkies and drive the Wizard out of Winkie country. She sends wolves, crows, bees and Winkie slaves to attack Dorothy and her friends, she even enslaves Dorothy when she cannot kill her (due to Glinda's powers) and tries to starve the lion.
In the film she is the sister of the deceased Wicked Witch of the East given her a motive for revenge, she threatens to set fire to the scarecrow, has Dorothy and Toto captured by her monkeys and threatens to drown Toto, and tries to put them to sleep in a field of poppies.
For a kids' villain she is bad and scary, although she is not all that powerful, she never completely defeats the Wizard and her powers are evidently weaker than Glinda's, and she meets her demise rather easily. Still the character is iconic and created an image of wicked witches that would last through the ages.

Next the Sanderson Sisters from 1993's Hocus Pocus. They are Winnie (Bette Midler), Mary (Kathy Najimy) and Sarah (Sarah Jessica Parker). Three sisters of Salem, in 1693 they lured away Emily Binx, a young girl, and murdered her, using her soul to restore their youth. They then turned her brother Thackery into an immortal cat when he tried to save his sister. For the murder of Emily and the presumed murder of Thackery they were hung for their crimes by the local villagers. Three hundred years later they are restored when virgin Max unwittingly brings them back by lighting the Black Flame candle on Halloween. Unless the witches can get their spellbook back from Max and his friends and create their potion to steal children's souls and successfully do so then come sunrise they will go back to Hell.
This movie is full of familiar myth and lore and does an excellent job of showing a good lot of it onscreen. The witches are servants of the devil, they feed on children's souls to keep their youth, two of them are ugly (and sensitive about it) whilst one is a seductive siren who uses her voice to lure children to them. Winifred is their leader, she is clever and can conjure electricity, Mary can smell children and Sarah the ditzy one can lure them. They have a spellbook, one made with skin that can see, they ride broomsticks, they can raise the dead (in the form of zombie Billy), they can turn people into animals (Thackery) and they are destroyed by sunlight.
The Worst Witch and Harry Potter gave us witches who attended school hidden from mortals' eyes. In The Worst Witch the villainous witches were Miss Cackle's evil twin sister Agatha and Ethel Hallow the heroine's intelligent but snobby, bullying rival who was unpopular with pupils but loved by teachers, particularly Miss Hardbroom. The witches wore typical witches' outfits with pointed hats, had cats and broomsticks and could cast spells and make potions.

In Harry Potter there were numerous male and female villains. Amongst the females Bellatrix Lestrange stands out best. A Death Eater, she is attractive and mad, she enjoys torture and took part in torturing Frank and Alice Longbottom, which led to her imprisonment in Azkaban. She also murders Sirius Black, tried to murder Tonks, tortured Hermione, murders Dobby, kills Tonks in battle, almost kills Ginny and meets her demise at the hands of Mrs. Weasley.
Bellatrix emulates the witches of the older films, the villain, she's wicked, murderous, insane and obssessed with torture.
Moving on to witches who seem caught between good and bad, Practical Magic and The Craft are the best examples I can think of.

Pratical Magic is a 1998 movie based on a book by Alice Hoffman and starring Nicole Kidman and Sandra Bullock as witch sisters Gillian and Sally. Sally tries to hide from the fact that she is a witch despite her and her children being painted as cursed and witches by the town. She does not use her powers and believes the family curse led to the death of her husband. Gillian is the wild rebel of the family, she left the town out of boredom and became involved in an abusive relationship.
Also featured are their aunts Frances and Bridget who try to guide the sisters but abandon them to deal with their biggest mess when it is kept from them.
The plot features Sally falling in a love with a man she dreamed up as a child and Sally accidentally kills him with belladonna in his tequila. They resurrect him with a forbidden spell from a spell book and kill him again when he attacks Gillian. He's not gone though and he haunts the house and possesses Gillian.
The aunts return, Sally accepts what she is and asks the townspeople to help her form a coven to save Gillian, which they succeed in doing.
There's not a lot of witchcraft in this movie, the aunts are the most traditional about it whilst Sally's is rarely seen due to her avoidance of it and Gillian's is reserved to mischief and gimicks. The biggest display of it is the resurrection of Jimmy.
Gillian comes across as wavering between being a good witch and a bad witch, she's not evil but she is reckless, careless and selfish and involves her sister in dark magic despite knowing the risks.

The Craft is a 1996 teen flick about teenaged witches starring Robin Tunney, Rachel True, Fairuza Balk and Neve Campbell. Sarah is a suicidal teen who moves house with her dad and stepmother and joins a new school where she is befriended by Bonnie, Nancy and Rochelle when Bonnie realises that Sarah is a witch like them and they need a fourth member to complete their group and strengthen their power.
Things go from bad to worse when the girls bring about the death of a man hassling Sarah by willing his death, and when Sarah's attempts to make student Chris fancy her turn into in a creepy stalker, Rochelle causes a racist to go bald and Nancy brings about the death of her wicked stepfather, and later kills Chris after he tries to rape Sarah.
The girls turn on Sarah when she believes they have gone to far, taunting her with illusions and dreams, trying to make her believe her father has died and then trying to convince her to kill herself before Nancy slices her wrists for her. Sarah eventually defeats them and heals herself. As a result Nancy goes mad and is committed.
The film decently deals with magic in different forms as it is the main plot of the movie and brings in the brief character of Lirio, an owner of an occult shop they try to steal of who is a good witch who tries to guide Sarah.
All of the witches waver between good and bad, intentionally willing about people's deaths and becoming obssessed with their powers to the point of turning on their own friend and trying to kill her.
Nancy is the worst as she is the most obssessed with power and brings about three deaths intentionally. Eventually this power drives her to madness.
The girls are a decent portrayal of a modern coven that is a stereotypical gothic teen vehicle.