We need email. It’s one of the few protocols that are 100% in the user’s control. I run my own mail server. I can’t do the same for whatsapp.
We’ve added a lot of checks to email (SSL, DKIM, DMARC, SPF) so it’s very easy to identify spam these days. It’s also easy to avoid giving any two companies the same email address. That’s something much harder to avoid with a phone number.
For 2FA, per-account email addresses and authenticor apps are the best approach for privacy.
I don’t even use it. Once I got SPF/SSL/DKIM/DMARC working, there was less spam than what I get on gmail.