I’ve self-hosted for 21 years.

I also run mail servers for others, mostly non-profit adjacent groups who don’t have the capital to be extorted by cloud service providers.

Sure, there are some things to learn, but like anything – if you do it properly, it’s not hard and can work properly. Never had any deliverability issues over that time (yes, even to the big providers). I also almost never touch the boxes (I do about one architectural overhaul a decade and am working on the next right now).

If you’re willing to invest the time and resources to do it properly, I agree, it works fine.