It's still possible not to be a serf imo. If you look into self-hosted alternatives to these things the communities online still have a lot of the vibrant and open spirit you're describing, built on collaboration, open protocols, and basic tools.
I very strongly felt the way you do until a couple years ago when I started following those communities and eventually started hearing non-technical people IRL start asking about how to cut toxic centralized products out of their lives. I think the internet that inspired you is still out there, maybe even the same or bigger in size, it's just harder to see because the larger centralized serf net is so distracting.
I'm not talking about hand-rolling solutions. WinAmp was just an analogy. An analogy.
Spotify sucks because it's a draconian walled garden. Yes, they have millions of customers. But there are no alternatives. They all want to lock you in. It sucks.
Back in the day, people were building tools left and right that were interoperable. They were writing importers and exporters and playlist managers.
It wasn't just music - there were tools for RSS and everything else you could imagine. It wasn't as "easy" as things are today, but there were so many novel things you could do.
Now it's all shrink-wrapped plastic that's rented to us. And we don't get to change the paint.
The world is less flexible, less free. Want another analogy? Look at modern Reddit and the disappearance of the 3rd party Twitter clients.
We're serfs.
It sucks. I hate it. Period. That's my argument.