From what I know of history, magic was feared and not looked at in a very nice way. People rumoured to be witches were burned alive and the Church declared capital punishment for anyone who indulged in anything voodoo. But today, our image of magic is pink sparkles and enchanted lamps and miracle spells. The most blatant example would be fairies - according to folklore, fairies are tricksters who misguide travellers. But today, we know them as pretty fluffballs who'll work magic into mending a dress or letting Cinderella attend the royal ball.
How did this switch in the stereotypes towards magic happen and when?
Well for one ur conflating a bunch of things together but I’ll try to remain succinct:
Your idea of how witches were viewed is misplaced somewhat. People who used magic werent always demonized, but a witch specifically meant someone who acquired magical power from Satan by trading their soul.
There are tons of references to good “witches” usually referred to in different terms that carries different connotations. An enchantress, a sorceress, and yes a fairy godmother are referenced throughout history without any indication of evil.
Fairy is a broad term and doesn’t mean one thing. Any magical creature can be referred to as a fairy (as far as Europeans go). But fairies while seen as tricky and untrustworthy are again fabled to be helpful and offering magical aid to humans all throughout their legends and myths.
pop culture changed our view of lots of things. The Wizard of Oz book is the first reference of a “good witch” For example. I vaguely recalled it caused a minor controversy to the point where Glinda is never referred to a a witch in the subsequent books. She’s referred to as a sorcereress and enchantress in most books. The term good witch was seen as an oxymoron. The wizard of Oz book and film and Disney altered the way we see magical tales and creatures to this day.
And finally: