alt Hacker NewsI’d be interested these stats broken down between domains associated with operating companies and personal or hobby domains.
The latter are likely to adopt much more slowly simply because of less perceived risk, lower payoff (no vendor reviews), and less dedicated technical expertise.
Just like personal sites were slow to adopt HTTPS. Mass HTTPS adoption happened once browser warnings and SEO incentives rendered sites mostly useless without it.
I'd expect the opposite really. Personal domains sending email are more likely to be run by MTA enthusiasts who don't have any money riding on others being able to receive their mails compared to corporate IT where mail is just one more thing they have to wrangle and really don't need the company leadership being angry at them because the spam-as-a-service company that marketing has been using without telling anyone gets blocked due to their DNS settings.