Cars, motorcycles, urban development, piloting, semiconductor engineering, etc... all have sizable active forums. Not every niche but in a lot. In those cases

Cars, motorcycles, urban development, piloting, semiconductor engineering, etc... all have sizable active forums. Not every niche but in a lot. In those cases Mastodon really is more akin to decentralized shouting into the void then a hotbed of genuinely valuable discussions.