While you could practically install macOS on ipads it’d work no better than windows used to work on tablets (it got a bit better nowadays). macOS is just not designed for touch input and would be a hideously subpar product. Can you imagine trying to use your fingers with the blender UI at 1x scale?
There is a toolset to easily get metal mac apps on iPad, though. I actually looked into what’d it take to port bender to iPad previously, and metal is the least of all problems. Blender is just a notoriously complicated piece of software.