That is very much a "depends on this" scenario. Very powerful ki martial artists (such as those in the DBZ universe, but they kind of take it to ridiculous extremes) and very powerful magic users can be devastating. If it's just "DBZ vs Mages". Pretty much DBZ all the time, since they can destroy planets at comparatively low levels compared to their ultimate potential. And while super powerful arch mages can probably devastate a whole country, continent, or even planet, I don't think I've ever heard of a mage physically taking out an entire planet in any mythos I've ever read

If you want to tame it down to just powerful ki martial artist vs powerful magic artes, then it's really just a matter of distance. In D&D a monk will pretty much decimate a mage if they're anywhere near. Probably withing 20 or 30 feet. But if they're like on opposing mountainsides or something or something, I'd say the mage certainly has the advantage