> What benefit do they see in exchange for the effort in open sourcing things?
Goodwill and more people willing to try whatever they release next, rather than the current situation of “Oh, Google is releasing a new thing? Pass. They’ll just stop supporting it and I’ll be left in the cold anyway, so no bother even trying”.
Killing so many projects makes fewer people interested in trying whatever they release next, which means fewer users, which means a higher likelihood it’ll be abandoned. It’s a vicious cycle that could be stopped or even reversed if they open-sourced their abandoned stuff.
To be clear, I’m not necessarily advocating Google should do it or that it’s be a clear win with no downsides. Maybe the upside wouldn’t be worth it, but there is an upside.
