Some channels did use it (Drive Plus comes to mind) and it absolutely destroyed their community. Their channel used to have really cool people you could talk to about cars, but it split that community, so now their main channel just has lots of hateful comments about the bad practice, their videos get tons of dislikes, and they get about 1/10th of the views on their videos (on the main channel) than they did before. Their viewership and comment sections are a graveyard now compared to how it was, all in the name of putting content behind a paywall. After all that went down, they lost one of their biggest talents, who started his own channel without a paywall and went back to doing things properly.
I've also seen this happen to a couple of channels who started putting exclusive content behind their Patreon paywall. Completely fractured their community and upset a ton of people.
Youtube just basically forced EVERYONE into a tiered content distribution model now. There's no world where this is good for content creators, especially at the absurd price-point they want. It's more expensive than Netflix!
While I'm sure some people might make more money somewhere because of this (mainly Youtube with their fat 45% cut) it's awful for the overall Youtube community and the overall goal that got Youtube where it is today, being able to freely share content with everyone. If this doesn't kill Youtube, I still think in a few years they're going to look back at it as a huge mistake...