It would be the only way I'd engage with their ecosystem. As is, my PS5 collects dust between big titles.
I think they would actually make more money offering sub service than charging $70 for their games, I would even argue they could probably even charge more than Game Pass and still grow faster and have more users, their titles are big enough for it. That's the thing but it would be a big risk to just jump in the pool like that so I can understand why they are going slowly. I guess they probably worry about getting into that sort of fight with Microsoft too.
Anyway I don't think Nintendo, Playstation or Xbox are going anywhere no matter what happens. Sony could buy out the entire industry and I still think Xbox and Nintendo will be ok and vice versa.