Sounds fair. If you essentially already have a TV or other device as a thin client, I can see many people happily paying $12 for 50 hours compared to spending $1000 on the entire console
Edit: Looks like Rockstar did the guy a favour and it was 6000 hours (https://www.nme.com/news/red-dead-redemption-2-stadia-player...)
This is from 2019: https://arstechnica.com/gaming/2019/11/stadia-launch-dev-the...
That is already a thing in NVidia Now, why would Xbox do it differently?