Hey now, it's not just lazy people, some people set up a mail server twenty to thirty years ago and don't care about all that newfangled tech like DMARC or DANE or IMAPv4.

Too many companies run on incredibly frail email configurations (while at the same time asserting that an hour of downtime on their email is a catastrophic business risk).

Configuring your SPF wrong but everything still sort of working because DMARC doesn't explicityly say anything can be a feature. I guess the time may have finally come for those companies to pay decades of technical debt.