I had a challenge to this idea, but after I thought about it more I'm going to take it in a different direction.
Consciousness seems to be an emergent behavior of at least some complex systems (what systems qualify is unknown). Just sticking with my own neurons, each neuron simply reacts to the signals sent to it and then sends out it's own signal. No neuron has the full context or is necessarily even aware that it's playing part in my own consciousness. Even I don't have the full context of what's happening in my brain.
If we extrapolate this to group behaviors then we can't assume any greater consciousness is any smarter than it's parts.
I joined during the great exodus and it's gotten better since then. At the time it felt like Lemmy's content was only consistently better than reddit at its worst, but that's not a high bar. I'm not sure how people have found it worse since most communities are still empty husks with like one post a week.