Hardcore gamers may not like it, but it's hard to argue against the observation that the overall trend everywhere is towards hosted services. Yes, there are some limitations imposed by physics but applications requiring specific high-performance local [client] hardware are going to be increasingly niche. (As, arguably, a lot of the most hardware-intensive gaming already is in the scheme of the population as a whole.)
I'm not a hardcore gamer -- I think hardcore gamers would call me a "casual gamer". But Stadia is not interesting to me at all. It offers tons of important limitations, and brings no actual benefit that I can see.
You can't see any benefit to never having to download a game before playing it or running 4K games without needing the latest gaming hardware? Given the obvious theoretical benefits regardless of how Google actually delivers on them, it's hard not to take your claim of "no actual benefit" as disingenuous.
I'm a very casual gamer and have no particular opinion about Stadia in its current form. And am perfectly willing to believe that it's pre-1.0 in its current form. But it's the direction things are headed.