I think the best solution to this is to use a hybrid cloud, phone and brain/hardware wallet. Fully self-custodial but with less stress on a person to always remember the seed phrase that may be loaded onto a hardware wallet if needed (if the phone+cloud is unavailable)

A service that is sorta like this is https://nunchuk.io/, also I think @#[0] is building something like this at Block with their own hardware wallet development, last I heard.