Yeah, PSNow has an impressively large number of games. But it's always had a lot of games. Sometimes I think the people who downplay PSNow haven't actually done any research into the service or what it has available. There's some great stuff there, and the thing that impresses me the most is how playable the games are, and how clean they look. My biggest concerns with PSNow was if there would be if latency was going to be a problem, and if digital artifacts were going to be a problem. So far, with my experience with the service, I haven't run across it. I want to say maybe once or twice there was a slight moment of artifacting, but other than that, it looks great. I haven't tried any PS4 games yet, though. Mostly just PS3 titles I wanted to revisit.
My hope is that they work PS1 and PS2 streaming into the service, since it's clear we aren't going to get any backwards compatibility with those consoles on PS5. I imagine the service would grow substantially if they offered that.