A creator with 2.1 million followers reaches, on a good week, 3–5% of them. The terms change without notice, because they aren't your terms.
An email list inverts every one of those numbers: 100% of the list, every send, on terms that don't exist because nobody stands between you and the people who asked to hear from you.
The conveyance costs $1,400 once. The asset compounds for the rest of your career.