And I would specifically suggest they sign in to desktop applications with Amber.

They can use Amber to sign in to both mobile and desktop applications. To my knowledge there's not a browser extension that can do the same and it would be two cumbersome anyways.

✅ Mnemonic backup.

✅ Less attack surface with only 1 app.

✅ Simple profile, app & permission management.

Starting a beginner off any other way is setting them up for failure. Imagine putting effort into a npub just to have your key compromised in 10 years after gaining 1 million followers.