Self-hosting email has been a part of my life since my high school days, I have a sort of attachment to it. I know "you shouldn't run your own email", but to take that away from me after deeply wanting one is too much.
In comparison, my job is just a job, I'm personally not too enthusiastic about it. I eventually plan to move to InfoSec or networking.
While I *could* move my domain to M365, I simply won't for my personal email.
I have ADHD, and don't want to make a mistake with two Outlook instances, one personal and one work. I'm a privacy nut, and want to separate my work and personal emails (Microsoft is better than Apple in this regard, but still).
I also contribute to FOSS projects, and using Outlook is an impediment to projects whose mailing lists are based on inline posting, like the FreeBSD and Tor mailing lists. I hate Rainloop (which I switched to after nasty Roundcube attachment bugs), but at least I can inline post.
(well, even at work I use Windows Mail instead of Outlook).