I think Google can fail quickly.

They really only have two things they're entirely reliant on, ads on search and youtube.

Search sounds like a sure bet monopoly, but it's in peril from their own research in AI. Anybody can generate any amount of realistic looking content written by an AI even about specific topics, and the AI can't tell the difference because it's made to sound like what an AI thinks is real.

They've already added rules that sites will get banned/blacklisted if they use AI generated content, but they'll have to hire people to determine that and good luck keeping up with spammers, who'll just click a button and generate new sites and content if they get banned.

Youtube is failing from self-inflicted policy wounds of showing people what Google wants them to see rather than what the person wants to see, so they are losing to Tik Tok, Rumble, and others because those sites are more fun and engaging. YouTube is becoming just a video player for things linked to from elsewhere, which means video can be put wherever gives the best return meaning that Google can't extract huge profit from it. Of course they could lift their bias filters, but their ideology prevents it.

They can't adapt because their internal systems are byzantine, taking half a year for new hires to be able to do anything, and with policies that prevent change. For example, for ten years they've been unable to add case-sensitive search because the UI team won't allow another button to be added.

So yeah I think they could fail in as little as 5-10 year timeframe -- not go bankrupt, but be completely dethroned.