Google aren’t interested in <1bn USD businesses, so it’s hard for them to build anything new as it’s pretty guaranteed to be smaller than that at first. The business equivalent of the danger of a comfortable salaried job.
Google is very good at recognizing existential threats. iOS were that to them and they built Android, including hardware, a novelty for them, even faster than mobile incumbents at the time.
They're more than willing to expand their moat around AI even if that means multiple unprofitable business for years.
Mobile is still nearly everything. Google continues to develop and improve Android in substantial ways. Android is also counted on by numerous third-party OEMs.
If you are a business customer of Google or pay attention to things like Cloud Next that just happened, it is very clear that Google is building heavily in this area. Your statement has already been disproven.