So yes, if the game(s) you want to play one of the included games and the service goes bust you don’t lose much. If you purchased a title and service goes bust then you likely lost that money.
Except I had to pay for the console $400, pay for PS Plus to play online $60/yr, and pay for games that I want to play $60/game.
But with PS4 I'm locked in to playing on my 1 TV at home or a small catalog of games I have very little interest in with PS Now.
With Stadia, if I can play the latest AAA games anywhere for $10/mo and the experience is rock solid 99% of the time, I'll be all over this.
The basic version is also free, which is something Sony isn't going to be able to offer me. But with Stadia I can play on my TV, on my desktop, on the go, etc.
I buy most of my games digitally whether or PSN or Steam. If either of those go out of business, I'm pretty much SOL. I don't see Google allowing you to claim your license for local copies as the Stadia hardware is specialized and custom, not something you can emulate easily outside of it's infrastructure, but that's a risk I'm willing to take.