because in the end most of the work you have with your selfhosted server is to figure out why MS (or, in my experience also google) rejects your mails and how you can fix it because you need to reach one person there.
i gave up and started to use a secondary domain hosted with a paid email provider just so i can reach people that my selfhosted server can't reach.
aside from that my selfhosted server is maintenance free.
But if you don't want to struggle with delivery to MS, you can always give up and use a (paid) relay. Although this feels like losing tbh.