Something else to keep in mind is that most Redditors nowadays (like Twitter and Bluesky users) are mobile users. I think a lot of Lemmy mobile apps have a good UI and solve that problem. However, it's hard to point new users at a single website/app/etc to join. Bluesky does that. Obviously, that's bad for decentralization, but Bluesky is also still a beta protocol that's headed toward decentralization at some point. Their single instance was necessary for them at the start.
When a new/small social media platform that acts as an alternative of a bigger platform pops up, one of the common topics on the alternative are people talking about how it's better than the old place and/or just trashing the old place. Eventually, they outgrow that (assuming that platform survives). I feel like that's happened with Bluesky. Browsing it, everyone seems to be talking about their own usual topics now, and I see very few posts calling out Twitter or comparing Bluesky to Twitter nowadays.
Lemmy still feels like it's in that "bash the old place" stage to me. Maybe ~20% or posts I see are talking about Reddit or talking about Lemmy in relation to Reddit. It's annoying.