I've been running my own selfhosted mail server setup for about six years [1] without much trouble. It's a lot of work in the beginning, and there is a learning curve, but I've never experienced any of the issues lots of other people seem to have with their setups.
Same experience here, used the workaround.org tutorial as strong inspiration (not blindly copy pasting, but to serve as guided path to follow and learn).
Steep learning curve indeed, but after initial setup it's just working and necessitate no tending except when I do major upgrades (of Debian so every 2.5 years on average), in case some config needs updating.
But this is really a private email server with no users except me, thus probably not encountering the issues related to mail servers with many users that might or might not have a good email hygiene.
[1] https://jschumacher.info/2021/05/running-a-private-mail-serv...