The issue with onboarding is the high barrier to entry in my opinion.
Figuring out relays, who to follow (and how to find their npub/nip5) are too difficult. I have seen external guides but we shouldn’t be giving links to users as they might not click them.
This really needs to be done on the client level as an introduction/walkthrough, but the process still needs to be simplified further.
Notice how the biggest drop is always within the first few days
