I mean, it's already pretty sketchy if we ever see a Mac version of Valheim, and that with an engine that is fully supported on the Mac and just a build away from being published. Why they don't do it is, well, not a mystery, it's most likely support. :P

A handcrafted engine has about a snowflakes chance in hell to ever being ported to the Mac.

So, no, I don't want to see them moving to their own engine. Unity is "good enough(tm)". Why change it?