It's not binary. It's a a gradient. You don't need the same self control to self custody 1000 sats as you need to to self custody a million sats. Can everyone be trusted to keep 1 BTC safe for a decade? Probably not. But you can probably trust most 10 year olds to keep 1000 sats safe for a month and most adults to keep 100k sats safe for a year.