Pleass introduce 2fa with sms. It makes you so much less vulnerable for loss of device. Replacement of phonenr. on new sim is very easy. Losing the device with auth. app is much more problematic: you lose access to mail
Get an authenticator app, SMS is less secure.
Yes, I agree with you and I know that ProtonMail staff also want to put it on ProtonMail, but they will need sms server to quickly send the code to users and the server cost is very expensive. So they still can't add it to ProtonMail