Andrew on Nostr: If I understand correctly, the reason it’s safer to input your private key on ...

If I understand correctly, the reason it’s safer to input your private key on native apps like Damus is because the key is stored locally.

If that’s the case, why don’t web clients like Astral/Snort/Iris/YoSup/etc store the private key in the browsers localstorage when accessing it from mobile? Is there a technical reason this doesn’t happen?