My skepticism is not (necessarily) based on the potential capabilities of future AI, it's about the distribution of the returns from improved productivity. That's a political - not a technological - problem, and the last half century has demonstrated most countries unable to distribute resources in ways which trend towards post-scarcity.

That may be your position as well - indeed, I think your point about "people think[ing] it's not possible" is directly relevant - but I wanted to make that more explicit than I did in my original comment.