I've heard an amusing conjecture that I'm not sure how much to take seriously unless there's a mind underlying the universe (like in simulation theory).

The void in its infinite time and endless space (the same as neither existing) became bored with itself, and in its attempt to destroy itself, split and created the universe we have now. Full of endless wonders and anomalies and beauty and travesty. All for the amusement of itself as one that remembers the abyssal void.

I don't think many worlds is strong enough, since it still doesn't say anything about why anything exists to begin with. You need something like the principle of plenitude.

Many-worlds doesn’t explain the complexity of the standard model at all. It merely gets rid of the arbitrariness and discontinuity implied by wave-function collapse.