My users went into their account settings and turned off all the online services without too much trouble. None of them care about this change. I gave them a heads up and bunch of info to manage it and they were just like “I can still find and play stuff so it’s fine, didn’t really notice”. 
I care about this change, because I have users asking me to stop advertising to them, stop blowing up their phones with notifications, and asking me about content I cannot provide or obtain. I’m glad your users have been intelligent or apathetic enough about it, but mine have not been.
Good. I don’t want you to tell me how I use my Plex account just because I’m connected to your server. I’m connected to multiple servers including my own and so are my users - how would that work in your mind when one admin turns off PlexTV and Online Services and the other doesn’t? What about if one admin disables watch indicators and the other doesn’t? That’s account level, not server level too…
Mind saving some of this perspective for Plex themselves? Why does Plex get to steamroll their users like this? Aside from that, why do you want advertising in your mobile OS notification drawer spamming you everyday? I can’t think of many people who do, and that’s exactly the behavior I want Plex to stop. If you enjoy advertising taking up your attention, time, and resources, fine, but don’t expect everyone else to. I cannot fathom why you would defend that.
For your other points, most of that is kinda basic business models that are annoying - ads and data mining and opt-out rather than opt-in - but you can absolutely turn them off. If you couldn’t turn them off that’d be very different. It’s not even buried or hard to do.
Except for new users, they can no longer opt out of the data mining that Plex does. This nullifies your argument here.
The one I think kinda fits enshittification is them changing course on remote access and locking it behind a paywall. That was a lock-in function they took away; for many it wasn’t a big deal because most local admins have plex pass and that includes ANY user remote access so was mostly a wash but definitely designed to push people towards a plex pass. I think Emby handles remote access better where you can either use managed users and free remote access or if you want “simpler” authentication you can pay for a hosted option.
Let’s not forget they took using hosted servers away as well. I’m lucky I don’t have the Internet connection I had 7+ years ago, but I’d be screwed if I did.
I think the term has gotten kinda skewed like “gaslighting” is used often to just mean lying instead of the more manipulative aspect it really means. So with that in mind… no I’m not thrilled with some of Plex’s choices and it’s soured me on their brand a bit and they definitely have harmed the customer good will and reputation they used to hold.
I mean…you’re describing enshittification. That’s what it is. And it does not stop, slow down, or reverse if we accept it as-is at any level.