As somebody who:
- Uses nostr (and prefers it)
- Uses AP via Lemmy & Mastodon (and likes it)
- Knows what AP and Nostr are and how they work and the pros/cons of the two network designs are
I also found this site confusing AF. It sounds cool and interesting, probably? I can't tell lol. Is it a network bridge operating at the level of a relay? Is it an app you can use to connect and post/read to/from both networks at once? What the hell is it?
It's done off-chain because on-chain would be expensive and slow. On-chain takes 10 min and $1.50-$15 in fees depending on the day. Lightning takes < 1 second for < 1 penny in fees.
Lightning transactions are secured by the base chain, so you're not at risk of losing any funds. The transaction data is "off-chain" because there's no reason for it to be "on-chain".