So I guess it’s not a bubble then since these companies are raking in the big revenues? Or maybe they are counting all those circular investments as revenues somehow?

You can make a lot of money but still be in a bubble if speculation is significantly higher than (actual or potential) revenue.

I think that's most people's assumption. It's not that AI is worthless, but that it's significantly less valuable than investors are betting on.

Revenue isn't profit, and the presence or absence of either, separately or jointly, isn't sufficient to determine there is a bubble.