I get where you're coming from. While I prefer not to, it would definitely help. Here's how I'd go about it if I'd implement such a system:

Create a nostr acc:

- Email

- Password

- That combo creates a keypair and logs u in (the site/app handles this)

- nsec/npub is encrypted with that same password, and the file is sent to the email provided (to prevent email host or others to get their hands on it).

- Alt: Sign in with Google or whatever. Same steps.

Side note: Still hoping for a wallet-like app for Nostr (HD nostr accounts) =3