@NogDogDec 13.2019 — #Much of what PHPMailer does has nothing to do with what the built-in mail() function does or does not do, but rather taking care of a lot of fiddly things you would otherwise have to do yourself if you just used mail() and wrote everything yourself from scratch.
PS: The SMTP stuff allows you to send email via another mail server using an account on that server, as opposed to being limited to the mail server running on your web server.