I’ve been running my own mail server since ~2002. For many years I was using qmail, of all things, on a home ISP connection. I wrote a semi-popular guide on adding spamassassin support to qmail. I was a true believer!
When hosting email from consumer internet became untenable, I migrated to digitalocean and Mail-in-a-box. To be honest, it’s worth the $15 to have a 100% always-on device hosting the email. I host lots of other stuff at home and having email be a separate thing makes it much easier.
They’re likely not fake; odds are there are loads of people who will buy this product and never have an issue. The problem is that some small percentage will experience catastrophic loss, and who wants to roll those dice?