I know this cliché is starting to fade away in literature, but I still believe it needs to be talked about. After all, in the future, this cliché could make a revival, much like the superhero genre in recent years. This is to set a precedent for any future writers out there, so the fantasy genre can continue to get fresh material now and again.
The cliché actually does not sound that bad on paper. After all, a wizard is a powerful supernatural being that is capable of creating mass amounts of chaos. Whether the powers are exclusive to one field or are god-like, it would seem an evil wizard makes for a strong villain. However, that strength of character fades after a while, when copycats think doing the same will help improve their stories. As a result, the evil wizard cliché has become a death wish for potential writers. A lack of originality hurts the plot of any story, even if it is focused on one detail.
The solution to this one is simple; stop making wizards as your main villain. Instead, try doing some research on other magical beings from Greek, Roman, or even Egyptian mythology and find your substitute villain there. As for the wizard character, mix things up a bit by making them the sole magical main character or make an anti-hero of some sort. There is still a lot to do with wizards in fantasy novels.