Substack handles emailing and payments well. Many people want to receive posts by email, which is a pain to do on your own with high deliverability. Some are

Substack handles emailing and payments well. Many people want to receive posts by email, which is a pain to do on your own with high deliverability. Some are willing to pay for it, and payments are similarly annoying (and benefit from a familiar interface, which Substack now provides).