Even though I love self-custody, it really is a huge sense of responsibility.  You have to desire self-sovereignty for it to be worth the perceived extra stress.  I think that what Obi is doing with Fedimints (where someone personally connected to you is self custodying the bitcoin for a group of people but not every single person needs to learn it in depth) is going to be more scalable.  

I hear people say that self-custody is going to get "so simple" but the more I hear that the more trust is involved.  If the people taking self-custody don't understand the basics for how to vet whether a self-custody solution is actually secure, eventually you are going to have a herd of people fall victim to marketing campaigns about self custody that aren't actually self custody.   Imagine for example how many people who own ledger hardware wallets are 1) not aware of the private key backup recovery they use on some devices and 2) wouldn't know why that was an issue even if they did know.  

The simpler you get with self-custody the easier it will be to push people into unsafe products in my opinion.