Have you looked into using Geforce Now with your friend? It's a fantastic service and works on OSX.
No where near as good and as stable as Stadia, also the monthly fee is a pain. With Stadia you can just buy the game and then play when you want, I don't think there is anything else like that.
It will routinely outperform a local series x (nevermind a PS5) given the right conditions, but that’s subject to your ISP, location, and probably not running CP2077 at maxed out ultra RTX graphics settings just yet.
Will give it another try.
The cloud time is the expensive part and most of the purchase price is likely going to go to the publisher. How many hours of gameplay before they’ve lost money on your purchase?