This is actually a lot more sane than you might think, and quite doable. There's no reason any critical data needs to reside on your phone, you can have it all on a different computer or cloud or somewhere safe.
Seeing the fact that every government, company, and criminal seem(s) to be highly motivated to exfiltrate data from your phone, perhaps it's one of the less safe places to store PII/critical data in the first place. (And that's before considering that it's highly portable and can simply be lost. )
If the critical data isn't on your phone in the first place, then you can't lose it.
But since your phone has network access, and as long as you have a decent data plan, your data need only be one tap away anyway.
Seeing the fact that every government, company, and criminal seem(s) to be highly motivated to exfiltrate data from your phone, perhaps it's one of the less safe places to store PII/critical data in the first place. (And that's before considering that it's highly portable and can simply be lost. )
If the critical data isn't on your phone in the first place, then you can't lose it.
But since your phone has network access, and as long as you have a decent data plan, your data need only be one tap away anyway.