I see something similar in a lot of tech-related threads too.
Just check out posts and comments about Corsair and AMD in particular. There is often no room for logic, facts or debate around their products on Reddit. Rather, threads feel like you're stuck in a marketing promo event where everyone feels the products are great and fantastic and can do no wrong. It's eerily like you're seeing a bunch of bots or paid shill accounts all talking to each other.
What I'm saying is that while tiny communities are great, the fact that they haven't moved to a federated platform yet doesn't really matter. Anybody, including yourself, can start up those communities on the Fediverse and curate them if there is enough of a reason to do so or just continue to engage them on Reddit too.