"while every Netflix subscription comes with a games library accessed via the Netflix mobile app, it’s unclear how many subscribers even know that the games exist. "

They're not, tho. You have to go to the App Store or Google Play and install each game as normal - they're not streaming. The only difference from any other game is that these require you to login with an active Netflix subscription to play them.

There's also nothing I've ever seen in the Netflix app that even tells you these exist, so they obviously don't care if users even know about it.

Are any of them any good?

Yes a couple good games actually. Into the breach and Terra nil. Like games I’d have paid money for