To me, it seems like most of Lemmy consists of users who are older millennials (born at some point in the 80s), male, and about 50/50 split between living in North America or the EU.
I feel like there's a really good amount of Europeans around, but I might just imagine that because I browse new at the times when Europeans would be awake haha
I think it's mostly because European are more aware of privacy, open source and such. I see that trend here and in many open source projects, and I browse on US times.