If Google had simply stuck at what they used to be, a solid search engine with some unobtrusive ads plus some other ancillary services, they could have sustained that more or less indefinitely. What can't be sustained is the endless growth that the stock market demands. If you dare to say "you know what, this is probably enough" you'll be immediately punished by the market.

We are seeing the counter proof right now. Search in itself isn't sustainable. The concept is challenged by GenAI-based approaches.

Of course they are not a 1:1 replacement, but for the first time we see Google's model being challenged and them having to defend, which they do by trying to drive competition of by integrating genai into their products. Once the competition is gone, they can reconsider.

There’s plenty of services that they could have gone into and charged money for.