Jeff, if we project forward to a time when base layer transactions fees increase so much, as to be unaffordable by the average user, do you envisage newcomers being able to onboard directly onto Lightning, but still avail of the self custody aspect, that gave Bitcoin so much of it's appeal, in the first place?
Splicing, batching & channel factories are all going to help, but ultimately, if the LSP has to pass the cost of channel management on to the customer, operating on L2 with self custody isn't all that different from operating on the base chain.
You've got to open/splice/close channels, have capacity in the tank to deal with channel counterparties who try to cheat, handle force channel closures, etc.
To the extent that we want to reply with 'Lightning', when the question of 'how will Bitcoin scale' is asked, at some point, are we acknowledging that for many, this solution is going to be a custodial one?