One billion people are not going to open channels. It's too geeky and complicated. There are custody solutions like LNDHub which allow people to open wallets within channels of custodial. Look at #[2] browser extension and Ln.Tips bot on Telegram.
Discussion
My concern is people won’t have a choice except to use custodial because the block capacity isn’t there.
To be fair a lot of Bitcoin is held in custody too, but people aren’t forced to use custody.
Let’s say the network handles the first 500m but not the next. Then custodial lightning providers will become centralised and we are back to the old banking system. Custody should be an option not the only option.
Bitcoin is a money layer. Lightning is a payment layer. It's ok for payment services to be custodial.
I know how to run a lightning node and open channels, but I do use custodial solutions in Lightning because there is more chances I lose money in self custody.
Okay so you are saying money is stored on Bitcoin. But Bitcoin can’t handle 1 billion transactions in the next 5 years. Or you are saying people use fiat for larger amounts instead of Bitcoin?
A Bitcoin transaction has multiple ins and outs. Look at exchanges: they are sending money to a hundreds people in on transaction.
Oh I see you familiar with bitcoin :)
Question was about lightning and how lightning custody brings us back to modern banking system.
My point here: the difference is in lightning you can't do a fractional reserve.