A common buttcoin argument is that people are happy having their money with a custodian who is backed by insurance, pays them interest, and protects them against fraud, theft, and extortion while still allowing easy access to their funds.
I don't actually have an argument against this. Not only do people have a revealed preference for custodianship of their money, but a significant portion of the general public is not capable of safely storing significant amounts of bitcoin.
Do you disagree? This, of course, does not imply bitcoin does not succeed as a store of value, but it does imply that "not your keys" is the norm and banks can presumably rehypothecate or lend with only fractional reserves.