still don't get that unless a certain instance de-federalizes others en masse, you're still gonna be able to access it's content and contribute from your instance. Sadly it just happened with beehaw.org, one large instance defederating another. That's a pretty big wall.

Although, in general,I wouldn't be worried. Even if a certain instance is getting big, you are still not subject to the whims of some venture capitalist corp in silicon valley. Sadly corporations love to control everything and always end up giving small startups offers that are too good to refuse and they either take it over or shelf it forever. I really don't want corporate control to return to the web. Reddit swallowed all the forums due to how convenient it was.