Neat, it's nice too see the numbers and analysis. Looks like Lemmy is enjoying healthy growth. It's also interesting to see the challenges people have when migrating from a centralized platform. I recall there was also a lot of confusion with the idea of instances when Mastodon started becoming popular.
In my view, the key aspect to focus on is sustainability. There are three things that are required for an open source platform to thrive. It needs developers to maintain the code and add features, volunteers to host servers, and users to generate content on the platform. I'd argue that Lemmy is already largely sustainable in all three categories today.
I think this is a key difference between open source platforms and corporate ones. A company needs to make revenue and show growth for the investors. This creates pressures to grow aggressively, and if the company fails to keep growing then it will probably die and the platform will disappear. On the other hand, open source doesn't have these kinds of pressures, and as long as a project can reach sustainability it can exist indefinitely without needing constant sustained growth.