What if you wanted to return early in the component? E.g. a hook has returned a certain value and you now want to stop all other execution and return null. With hooks you can't as that would change the order.

Yeah but you also wouldn't try to return in the middle of function argument declarations. I know it's a little weird, but just treat it as a declaration block and you won't have any problems, what you're proposing is impossible with react architecture as a whole anyways (because the next component would get wrong state cells, it's a stack).