I think we may just not view Lemmy in the same way. I don't see these sites as "fun". Sure there are funny memes, but it's also news and meta discussions about very recent topics. If I wanted to open something to have fun it'd probably be a video game or something.
Big tech makes it easy for people to use. They want the biggest and bestest userbases with the simplest interface... Lemmy does not care how big it is, it's all about organic growth, and Lemmy by itself doesn't have a very nice interface. I'd bet most people come here because they want to get away from the others, not because they want to add it to their list of feeds to browse. That being said, people making an effort to get away from the biggest and easiest platforms are probably more likely to put effort in to cater their feeds to their own interests and viewpoints.
Also I must've misunderstood your comment on Patrick originally so that's my bad.