Just to be clear I’ll define two things:

• “knowledge” - info available to the person from memory; or to the group, through their common channels of interaction. The opposite of “ignorance”.
• “intelligence” - ability to use said information to produce logically correct and relevant statements.

This is important here because, even if your complain is worded as Lemmy being less intelligent, you’re clearly complaining about lack of knowledge - cue to “I always learn new stuff” and references to the complexity of registration (i.e. the knowledge necessary to navigate through it).

With that out of way:

Lemmy’s knowledge is mostly impaired by a small userbase. It’s great when it comes to a few topics, such as technology or specific lines of political thinking; but once you go past that it’s hard to find a lot of stuff here. This is not does not mean that the individual users are ignorant - sometimes you know something but there’s simply no room to convey it.

Intelligence-wise, however, I disagree with you. Don’t get me wrong, a lot of Lemmy users are braindead trash that would genuinely believe that 50 is 100 because it is not 0, eager to vomit “ackshyually” (a sign of knowledge and stupidity), fallacious as a brick, so goes on; however, they’re proportionally less of an issue than the morons that you’d find in Twitter, Facebook, Reddit etc.