I think wide adoption of this will help a lot with self-custody. https://github.com/satoshilabs/slips/blob/master/slip-0039.md

Use multi-sig to control spending. Use SSS to control account recovery. Lots of possibilities to create best practices for normal user experience. Just need more experimentation in this area.

Check out the docs on Argent "guardians" for how SSS can be implemented in a wallet: https://support.argent.xyz/hc/en-us/articles/360022631992-About-Guardians