As people are mentioning, Aqua wallet, Misty Breez, etc feel like the prime use case:

A "semi" non-custodial wallet that you can onboard your friends to. Or even onboard small countries to.

It doesn't mean repeat users need their funds locked to liquid indefinitely. Only that you can get around doing LSP stuff at the onboarding time. You push true non-custodial off to a later date.