Yeah I'm actually less hesitant to try out Google open source projects than I am new Google products. I have no idea if this is accurate or just my impression, but I feel like I've been burned by the "killed by Google" meme almost exclusively on their software products, whereas there are plenty of open source efforts from Google that I think of as stable.

In addition to the ones you listed, I'd add the V8 runtime, Jax, Protobuf. Even some of their projects that wound up declining in market share (Angular, Tensorflow--both losing share to projects that wound up at Meta, ironically) are still actively maintained and pushed.

But I'm sure there's also a huge graveyard of open source projects they abandoned that just never hit my radar. Still, at least with their open source stuff, you can fork in the worst case.

Or if it becomes commercially valuable, then you can expect Google to take a third direction (embrace, extend, extinguish) : a la their current approach with android

Don't forget `cgroups`, eh? That was a huge Linux contribution.

or Android Open Source Project?

There is an assumption that AOSP is how OEMs receive Android updates from Google. However I am not sure that is the case. GrapheneOS is perhaps a minority player due to lack of hardware which they can use to get into a partnership agreement and advanced access.

more like create a big launch for promo, then maintain it briefly then slowly let it die

A recent example was the Google workspace CLI, which was maintained for just a month: https://github.com/googleworkspace/cli