It's not insurmountable to set up initially. And when you get email denied from whatever org (your lawyer, your mom, some random business, whatever), each individual one isn't insurmountable to fix. It does get old after awhile.

It also depends on how much you are emailing, and who. If it's always the same set of known entities, you might be totally fine with self hosting. Someone else who's regularly emailing a lot of new people or businesses might incur a lot of overhead. At least worth more than their time than a fastmail or protonmail subscription or whatever.