I think Sony understood that consoles will become the choice for "serious" gamers, who want the highest gameplay quality, low latency, excellent framerate, no video artifacts, VR, 4k, etc...
On the other hand, streaming will be for casual players who don't care too much about the latency, video quality, etc...
Probably we'll be able to play PS5 through streaming on the day one for 14,99/mo. But with all the issues related to streaming, want the best experience, buy the console.
So PS5 will be directed to hardcore (in the meaning of who wants high-quality gameplay) and is disposed to pay for that.
Sony is well-positioned in these two fronts (Consoles and Streaming).
Of course, PSNow will receive a huge upgrade with the release of PS5.