I read this with some interest because I've self hosted personal email since about 2001, with experience in email management going back to 1995. The challenges presented are certainly true enough, but I still think self hosting is still worth it. I'd rather not share the management of private keys with DNS (DNSSEC) and email service providers (STARTTLS, SMTPS, DKIM, POP3S, IMAPS). I'd like to keep them, well, private. It also provides the opportunity to see the mail queue, and mail server logs. I find that helpful.