I like to imagine that instead of dragonball characters being insanely powerful, it is actually the universe they're in that is incredibly fragile.

I've never really bothered to separate "ki" from magic anyway. They can be functionally very similar. As far as I'm concerned, ki/chi/qi is a form for magic.

Imagine a very powerful support mage who has access to bravery, faith, haste, protect, shell, quick, and all that, then casting it on themselves to gain superhuman physical abilities. Sounds pretty similar to ki to me.