So... I don't think this is certain. A surprising number of people pay for the ChatGPT app and/or competitors. It's be a >$10bn business already. Could maybe be a >$100bn business long term.
Meanwhile... making money from online ads isn't trivial. When the advertising model works well (eg search/adwords), it is a money faucet. But... it can be very hard to get that money faucet going. No guarantees that Google discover a meaningful business model here... and the innovators' dilema is strong.
Also, Google don't have a great history of getting new businesses up and running regardless of tech chops and timing. Google were pioneers to cloud computing... but amazon and MSFT built better businesses.
At this point, everyone is assuming AI will resolve to a "winner-take-most" game that is all about network effect, scale, barriers to entry and such. Maybe it isn't. Or... maybe LLMs themselves are commodities like ISPs.
The actual business models, at this point, aren't even known.
But not profitable yet.
https://finance.yahoo.com/news/uber-technologies-full-2024-e...
They invested tens of billions of dollars in destroying the competition to be able to recently gain a return on that investment. One could either write off that previous spending or calculate it into the totality of "Uber". I don't know how Silicon Valley economics works but, presumably, a lot of that previous spending is now in the form of debt which must be serviced out of the current profits. Not that I'm stating that taking on debt is wrong or anything.
But the way it usually works for Silicon Valley companies and other startups is that instead of taking on debt they raise money through selling equity. This is money that doesn't have to be paid back, but it means investors own a large portion of this now-profitable company.