On chain isn't always expensive. It's often quite cheap.
I think lightning is just not a great solution for poor people. (I need to learn more about quasi custodial wallets muun, breez & phoenix. Those might be good for poor people.) Fedi mints will be awesome, but until then i would probably recommend poor people use liquid (yes liquid) or on chain over lightning.
And Lightning was made to sink the barrier to entry. Can't it go lower?
In theory, yes, but there's a lot more work to do. I think fedi mints will get there before lightning gets there.