Since there’s many different sources (federated) instead of a single one like Reddit, maybe how you’re connected and being fed things is limited, giving you an impression it’s less. It was much worse in the beginnings obviously, until moderators and instances grew and learned how to better pump things out. It still has its issues, depending on where you are.
It’s also not equal to compare a still new network of Lemmy and others to a long established Reddit structure of niche subs for everything. At some point there were none of the subs we now see. Maybe some of them aren’t needed at this time, as setting up a new community is not hard to do (moderating it and growing it is work though).













Federation and how things are pushed out is complicated. World is pretty big (it was one of the initial places during the first growth spurt from Reddit) but I don’t know the current state of them allowing material from other instances. I think it’s okay, I see a lot of world users in my feed, but I don’t know what THEY see.
The caveat of making other accounts is that they are different accounts, so your posting and history are only there (although there was research on ways to transfer or share, but I don’t know where that is atm). But if another instance is open to new signups, nothing wrong with trying them out, see if you see things differently, end up using that one if it feels more open.
Go visit https://lemmyverse.net/ and see what’s out there. There’s three big “types” now, Lemmy, Mbin, and Piefed. I can’t tell you which is better, as everyone has their own take on things.