Personally I’m a fan of the holographic principal. The universe is encoded on the event horizon of a black hole and our black holes create other universes. Then “why” just becomes a matter of waiting for the right conditions to come along, because with infinite universes it has to happen eventually.

PBS Space Time has done a LOT of videos on the topic. There’s no experimental support for holography, but there is a ton of circumstantial and mathematical evidence to suggest that it is worth taking seriously.