If the universe (our experience, our lives, our physical reality) weren’t complex (unpredictable, undecidable) what would it be?

This is not rhetorical question.

It is not easy either.

Can you imagine an alternative?

It would be useful if we could so we can go look for evidence of the thing you imagine.  Why would we do this?  The growing research in “complexity” and “complex systems” make some assumptions based on irreducibility, computation equivalence and so forth that suggest less complex things are not capable of universal computation, and in some sense, the ability to evolve ever more interesting/complex things, like our universe.