[qsera]

>Why this limitation?

This is not a limitation. The basis of this idea is that there is consciousness in this (our) world. So we know that consciousness can result from our set of physical laws and the set of all random events in this world . That is the only thing we know for sure, and the only place we can start reasoning..

We don't know if it is possible for consciousness to exist in a world where everything is random, or less regular..

[GoblinSlayer]

It's easy to define: a world the same as our world, but has an additional random phenomenon, humans would still exist. Mathematics is fantasy, you can postulate anything you want there.