I’m a proponent and I definitely don’t think it’s impossible to make a probable case beyond a reasonable doubt.

And there are implications around it being the case which do change up how we might approach truth seeking.

Also, if you exist in a dream but don’t exist outside of it, there’s pretty significant philosophical stakes in the nature and scope of the dream. We’ve been too brainwashed by Plato’s influence and the idea that “original = good” and “copy = bad.”

There’s a lot of things that can only exist by way of copies that can’t exist for the original (i.e. closure recursion), so it’s a weird remnant philosophical obsession.

All that said, I do get that it’s a fairly uncomfortable notion for a lot of people.