I’ve seen a lot of claims that AI will dramatically increase revenue. If this is true across the whole economy, where is this extra spending coming from?

So I am very ignorant, as this question shows. But I've been wondering.

Simplistically, it seems that revenue comes from people spending, and they already spend about as much as they can. And it doesn't look like there is a race to give people more spending power as a whole. Even if exploiting AI helped workers create more value to sell, without people generally having more to spend I don't get how total revenue would increase.

So for companies that can successfully use AI, would it be more accurate to say that they see themselves as fighting to gain an extreme competitive advantage? Like two people struggling over a gun? So that AI wouldn't increase total revenue, but it could give some companies the chance to take over a larger part of their sector?

For the overall affect, it seems like it would lower total revenue for the country. There would be pressure from resources being diverted to create and run AI. Which could make those resources more expensive for other things. It also ties up cash that would otherwise be used to pay workers. (As with Oracle.) And it does have the potential to replace some human labor.

So it seems like it's pretty massive expense, and I'm not really seeing what the payoff is. For the country, I mean. It kind of just seems like a few companies are doing a good job of capturing processes of attention, choice, and labor.

Anyways, I'm sure my whole question has a ton of obvious errors and blind spots. If anyone wants to point them out, I'm happy to learn.