Playstation has been sitting pretty for a long time now, PS1 and PS2 were the perfect game machines, and even if the 360 did great, the PS3 also did great, eventually.
Sony didn't need to change its model, it worked and the PS4 was the clear undisputed king, they only needed to grow. But with Game Pass, Sony realized that Microsoft is about to go big, they are not gonna build something like Game Pass without being willing to spend a lot of money. After hearing rumbling about studios being bought up and with the looming next-gen, Microsoft and Sony have been reading their guns, to be the king you need the exclusives, and with Xbox going PC, Sony also understood that they needed a ubiquitous brand like Xbox that crosses PC and consoles. Sony has been and is still playing a bit of catch-up, even if they are still the biggest right now their model isn't going to work in the future if Xbox continues to be this aggressive. So they are getting aggressive too.
Both Sony and Microsoft are aware that something like the Nintendo model is never gonna work for them, they won't be able to have a billion-dollar business based on console exclusivity, brand power, and lower-powered hardware, they don't have Pokemon and Mario or the family-friendly approach.
Right now it's the law of the jungle, you eat what you kill.
