As someone who has moderated multiple subreddits, and single handedly brought a subreddit from 0 to 100,00 subscribers, this misunderstands subreddits, moderation, and the relationship between Reddit and moderators. IMO subreddits were supposed to be like random forums on the internet of old, but with a shared substrate. Those forums were singularly owned as well and if you didn't like the operators you moved on, because there was no one you could escalate to.
There is fundementally a social contract between Reddit and its moderators. Moderators get autonomy and control, and reddit gets content that keeps users around. As long as Reddit does not pay moderators, autonomy and control is all they can give moderators. I'm investing a lot of effort, and I'd like to retain some control. IMO creating a community is more like starting an open source project on Github with a lot of community contributions.
If you take away autonomy and control from moderators, what is in it for the moderator? Imagine if github started seizing projects wholesale, taking them over and installing new maintainers. People would move off the platform.
Some people say that moderators are unpaid employees, but IMO that is only to the degree that moderators are required to carry out Reddit's agenda and priorities. We don't call OS maintainers github employees. I don't mind if Reddit benefits from my communities, as long as I can run it the way I want. If you take away autonomy and control, moderators absolutely become unpaid employees.
If Reddit didn't like my policies and took my subreddits, I would take that as a strong signal that Reddit is not the place to build my communities. The API debacle, protests, and mod removals caused me to decentralize my community more. I spam a linktree in my subreddit that links to Discord and other resources, exactly to protect against community seizeure by Reddit.
I think you touch on some real issues. One is of namespacing; folks can sit on valuable portions of the namespace and basically extract rent. We have the same issues for domains, and haven't solved it there. Some places like github semi-solve it by putting repo's in organizations, but that shifts the namespace issue to the organizational level.
The other problem is second generation moderators. Most moderators are terrible at succession planning, and so generally chose terrible successors. Many second generation moderators don't understand the original decisions that shaped the community, and what makes the original community successfully. Reddit should do more to encourage succession planning, and teach moderators how to do it.