I think the third is indirectly linked to the second thing - I'm sure there are people who joined here posting about or trying to find posts about their interests outside of Bitcoin/Nostr but since these posts do not get surfaced easily to a borader audience, it can feel isolating.
Also, new users write to free relays which further reduces visibility to the non-bot people here.
There's only so much people can post without engagement before it feels like talking to the void 😅