Presumably if Google makes game development for Linux commercially viable, that will make for much more vibrant community support (tooling etc.) for local Linux as well. That plus what Valve is doing with Proton could potentially break the stranglehold Windows has on PC gaming. I personally would go 100% linux on my media PC if I did not occasionally play games on Windows.

I think a lot of people don't expect games released on Stadia to ever be downloadable. It won't help linux at all.

They most likely wont be released, but the hope is that google contributes to open source like vulkan, linux video drivers, graphics rendering, as well as potentially release their own tooling.

Some of them not (from legacy publishers). Others from normal ones will, especially since they'll see it as "why not reach more users, we already did all the heavy lifting anyway", instead of legacy publishers' scornful "why do it, who is using Linux?".

In their context, lock-in could happen if they'll start pushing exclusives. But in technology sense, they are advancing common stack (Linux / Vulkan), unlike MS and Sony who use tools lock-in to discourage platform development by making it more costly.

Can you explain how its not a lock-in? It seems to require a Google account and is limited to games that are blessed by google. AFAIK, I don't think I can download Stadia and run it on a home server and stream games to multiple PCs in my own home. If Google made it open source, then yes, I'm 100% with you...

Lock-in as in requiring to use Stadia to get certain games. Store lock-in (exclusivity) isn't much better than technology lock-in.