> But I cannot help wonder how life might have been different, and if I really did have a chance to change to world.

You made the right choice. Life as a PhD student is ultimately a life of poverty and uncertain future. You might get lucky and be able to explore a meaningful research topic, but more often than not you would end up in a miserable path with no future, and with the best option at securing your material needs to be in an ungrateful and very hard to reach academic role.