How to generate virtual online IDs to prevent spam, scams, and phishing attacks

So many cybersecurity vulnerabilities exist on the internet nowadays that giving out your email address or phone number when signing up for a service is akin to giving someone your full name on the first date. Recently, a string of SIM swapping hacks have occurred; attacks in which hackers take control of your account by stealing your phone number, claiming ownership of it through your mobile carrier, and using it to bypass text message-based two-factor authentication.
As attacks like these bec