The "general public" is incredibly stupid.
I don't see how self-custody in its current state is even feasible for 90% of the population.
We're talking about the same people who would go buy gift cards to pay "the IRS" when someone with an indian accent calls them.
We already see the shitcoin space and how retarded people can be with a) financial decisions but more importantly b) with securing their keys. And that sample of idiots is above average when it comes to tech literacy.
Things like Bitkey that abstract securing the private key away from you are a good first step but even that isn't idiot proof.
Is the average joe doomed to rely on custodians due to their own stupidity? Bitcoin isn't fiat, there is no undo button or a bank to eat the loss.