I guess it depends on your view about the greater "purpose" of Bitcoin.
While self-custody is obviously the optimal way to hold bitcoin, I don't believe having the ability to self-custody is the be all and end all of Bitcoins existence. You can already self-custody fiat cash.
Everyone doesn't need to use bitcoin natively for Bitcoin to fulfill its objectives.
Most will use it custodially - even bank with it! And that's perfectly fine.
The most important aspect is that it can't be debased by governments.
(all in my opinion of course)
And i guess to bring it back to your post, that is to say LN works great when those facts are accepted.
Bitcoin replaces central banking, not retail banking.