The reality is if it isn't ads or ads adjacent, Google will lose interest. And based on their historical revenue I suppose they ought to continue with this model.
If Google spins up a project and then abandons it, how could they possibly be harmed by someone else offering a comparable product? Google has already accepted a total loss on the product, there's really nothing for them to lose here.
It's certainly a win for the rest of us, but how does Google benefit to make it a "win-win", and not just a "win"?
Next (good) thing they build will probably have greater adoption, due to less fear of "they'll kill this in two years anyway".