FACT: you are not smart enough to not use two-factor authentication on your primary email.
If you are targeted by a spear-phishing operation, you will fail.
If you lose control of your primary email address, you will also lose control (via lost password recovery) of all your online accounts and probably of your phone and other devices as well.
You don’t need to be famous or important to be a target of a spear-phishing operation. Thanks to countless data leaks over the past decade, your identity has already been leaked to hackers. It’s not a question of if but when.