Those numbers sound... unrealistic to me. Just doing some napkin math: 65 $/user/month / 0.01 $/ad ~= 6500 ads/user/month, which is about an ad per minute if you assume someone is using the chat interface 4 hours a day including weekends. Maybe you see that behavior from "my GF/BF is AI" types but I'm also already assuming 0.01 $/ad which is super high to my understanding (if you work in adtech please correct me if I'm wrong). I don't forsee over 50% of your workday or leisure time spent in ChatGPT as likely, especially if the ad rate is well beyond YouTube's nigh-unusable amount it is now.

There's never going to be 65$/user/month, they already struggle to move past 5% of paying users with the current pricing.

Some companies going under doesn't change anything about the market as a whole.

If the demand is real and the company just sucked, their users and infrastructure will end up at a competitor: the value for that one company is bigger, but the overall per-user bill remains about the same.

If the demand is fake the infrastructure will be sold off at a big loss, allowing new companies to enter the market with far smaller investment costs, allowing them to undercut the competition, driving down the price users expect to pay for compute, resulting in a race to the bottom between the remaining AI companies in an attempt to attract enough users that their hardware won't sit idle - which in turn makes it far less likely that they'll be able to hit those revenue figures. And a bunch of investors just lost a few billion dollars, of course.

And the rest still bought RAM, GPU and datacenters.

What a giant waste of resources that are missing elsewhere

Well, even these AI companies cannot manage to replace these workers themselves.

the big question is: who would pay for those services then?

I mean I love simplicity, and if economy could be simplified to a big money printer machine directly printing the money to a burner, then it would be so simple, that even a short context window could comprehend the economic cycle finally!