It is one thing to have alternatives, but to actually execute the switch to alternatives seems near impossible. Breaking away from Google is already hard, breaking away from Google + Facebook (which has your phone number on WhatsApp) seems impossible.
Not to sound too personal, but I thought everyone pretty much gave in to Google already.
A lot of us use services like Fastmail, Protonmail for email and simply do not use Facebook. Gmail is so bad it's not even usable for me in comparison to how it was several years ago.
Changing your email account is easier than you think, especially if you already use Password Managers like most of HN will be doing. You can redirect email from Gmail to your new email address, and at your new email provider put a footer into your every sent email which states you've switched to this new email address. I advise backing up your email from Gmail using Thunderbird just in case, but personally I've never had to access the backup, it's really much easier than you imagine.
Actually I'm talking about Google account and services in general, not just gmail. Google account also exists as an IAM service for various Google branded products, such as YouTube, and a lot of other external services, which use Google account as the preferred or only authentication method. It is much harder to break those once you are locked in.
I suspect it will ultimately be upended through a deeper change, likely with agent based computation.
If I may draw another parallel:
There are also loads of people out there who can migrate out of the system (China/Google) if they don't like. And those who stay with the system (China/Google) seems to be fine with the system knowing their identity.
People on HN are terrible with email. How on earth is it possible to think Gmail is the only option for email, a decentralized, standardized service? How ignorant do you have to be to make that assumption?