Client hopping is cool just use NIP-07 on the browser and burner keys if it's a new client you don't trust.

When key delegation is more widely adopted no one will be using their main key to sign in to any client anyway. You'll create a separate one, delegate permissions from your main one to it, so it posts notes on your main key through another one.

If the login key is compromised just revoke permissions. It's no longer an issue that can cost you your whole "account."