I should have been clearer, I was referring to PS Plus numbers (47m+), which is think is just as relevant of a comparison if not more since it focuses more on newer modern games compared to Now's legacy stuff. Maybe the comparison is made because of streaming element, but I don't really hear people talking about using that with GP, it's just the "free" games and at that level Plus should be in consideration IMHO, certainly it's numbers shouldn't be discounted entirely.
There are several reasons for that:
- Xbox Cloud streaming is only available to GP Ultimate subscribers and the number of compatible devices was very small until a few months ago (only a few high end Android phones / tablets)
- most people subscribing to GP Ultimate instead of the normal GP sub already have Xbox One (or Series) hardware (or gaming PCs) which run the GamePass games much better locally than streamed
- Xbox consoles aren't supported Xbox cloud devices (yet?)... so you can't skip a 50 GB download of a GamePass game by steaming it on an Xbox console. And you can't stream Xbox Series games/versions to an Xbox One S for better performance / raytracing effects
- Save data sync for some games is extremely slow (f. e. Forza Horizon 4... probably all my DLCs / bonus cars have to be installed to the virtual Xbox, which is a blank slate every streaming session)
- Xbox cloud streaming quality was really bad until last week: 720p streaming with video artefacts and Xbox One S performance
But things got a lot better a few days ago: https://news.xbox.com/en-us/2021/06/28/xbox-cloud-gaming-now-running-on-xbox-series-x/
Now the Xbox games run on Series X hardware and are streamed in 1080p 60 fps... probably with some supersampling advantages for games that run in higher resolutions than 1080p on Series X hardware. With Windows PCs and iOS devices the compatibility for Xbox Cloud streaming has also gron immensely in the last weeks.
That said, PSNow streaming also got a lot better since April with the upgrade from 720p streaming to 1080p streaming (for PS4 games). PS3 games are still streamed in 720p as far as I know and streaming is the only option for PS3 games in that subscription (they can't run locally on PS4 / PS5 hardware and PS Now doesn't support PS3 hardware).