The multiverse isn't falsifiable. It's philosophy, not science.

>And by the way, can't multiverse thinking be invoked pretty much anytime to explain anything?

That's exactly the problem I've always had when it comes up.

Anthropic bias doesn't explain anything. It just says that you can't use your own existence as evidence of something. Because if you didn't exist, you wouldn't be able to make the opposite argument. It's basically just a wider application of survivorship bias. It works whether or not there are actually other universes (although the existence of other universes definitely makes it more intuitive to understand.)

By itself that may be true. As they say, "painting the target around the arrow" proves nothing.

But what if the target was there before? Then you have to explain how the arrow hit it so perfectly. There is a difference.

The difference is, is there anything special about the target's placement?

One can argue that alternative universes where soups of particles didn't give rise to life are all uninteresting.

You can of course say that life is needed to make the judgment for what is interesting.

But are you sure there is no sense in which the target can be said to have been painted before the arrow was fired? It all rests on that.