Yes, despite the complaints I have aired, I think this place is a lot better than many others, precisely because I was able to air them without reprisal from staff. But, communities and staff change. There was a comment from another user that stuck with me (paraphrased):

to ensure freedom of speech on a site, there needs to be a technological component and ensuring it remains free.

If individual moderators can do site-wide harm, this or any other site will eventually deteriorate. If a site only remains free until the first time that nepotists manage to get into site staff, then it will forever remain only a question of time for any free site until it goes the same way as any other social media site appears to go. Entryism, collectivism, identitarianism have been the bane of every social media site. This is nothing new at all. All of the current worst offenders, be it Twitter, YouTube, Reddit, have all advertised themselves in the beginning stages as free speech platforms.

What has changed? Why does freedom always appear to diminish over time? How do some of these crazy people end up calling the shots on those sites?

Different people will have different answers to those questions. But if a site is explicit in this goal, like drafting a constitution that one can fall back on perhaps, or limits the ability for such a takeover by design (in software) then that might be a better way for a site to endure long term.

It's also a common pattern of communities on sites to "declare it dead" at the first occasion of frustration. People have a short fuse and little patience, probably justifiably so, after having had their trust abused so many times. Often times, people who say that they oppose censorship really only oppose them being censored. They have no issue with implementing precisely the same sort of censorship that drove them from the previous platform they abandoned out of censorship. The risk of such people ending in positions of influence on a new site spikes after every wave of influx of new users.

Either way, I think it would serve people well if they reflected on the root causes of the life cycle of such sites. And maybe it is just a natural and expected life cycle of a site, that it runs its course and needs to be replaced eventually. By software industry standards, some sites have been pretty long-lived before they have changed direction. However, there will also always remain a cycle of people fleeing from platform to platform if every platform can be taken over by infiltration of its site staff. I don't think we should have to abandon a site every time a bad actor manages to infiltrate admin ranks. But, that is the cycle we are stuck with for now, because many people seem to lack the introspection how these patterns are carried from site to site, how the seed of that is sown at the inception of every new site. There are definitely people who seem better morally and ethically equipped than others to not abuse the powers vested in their position as moderators or site staff. Most seem to quickly go from near free speech absolutism to being little tyrants, Napoleons in the making, as soon as they receive an inkling of influence or power over others.