I actually think Nostr has the easiest onboarding even. When explained simply:

1) Download Primal
2) Generate NSEC (don't lose, don't share).
3) Start posting.

Onboard in under 20sec just like it should be.

The confusion I get from others lies in the Nostr's structure. The "well how does it work if it's decentralized" or "what are clients, relays, protocols, zaps, events, etc".

I just skip explaining all that at the start so they can just use it first. Let them fill in the blanks later via exploration.