My belief is sony is limited to around 100-200 million users if they don't do something differently. That something could be cloud gaming available in any platform, portable console, playstation games coming for phones or pc's,.... It's very logical for sony to test pc market and see if it would make sense to expand there. Those who are not willing to explore, change and grow are bound to become extinct.
They talk about a new strategy for cloud gamins using Azure Server. This is the way to go for them if they want to keep third party on PSN ecosystem. Nintendo will not change a lot and they will live because game sales come mostly from their own titles.
If tomorrow every playstation gamer stop to buy a Playstation or use any new cloud Playstation services and go buy a PC they will be nearly extinct because more than 80% of the revenue will disappear. Hardware(PS4,PS5 and PVR) + third party PSN + third party physical games + is probably around 85% of SIE revenue