The problem is that lightning is basically federated Paypal. You have to trust your specific provider to some degree. If he stiffs you, you can get arbitration on-chain. There are almost zero barriers to entry so Paypal can be replaced by Paypal 2.0.

I don't believe for one second that when you increase the size of the audience that anyone will care which provider they use. In practice that means they will just use Visa, Mastercard and Paypal, maybe even by skipping lightning entirely.