IMO the only truly difficult part of self hosting is mail delivery because you end up at the mercy of big stupid companies (eg Microsoft) that don’t give a shit. Even then it is possible and possibly advisable to use a paid service for delivery and let them deal with the bastards.

With a bit of research and a methodical approach I think just about anybody comfortable setting up other linux network services should be fine. I like being in control of my own mail store. I choose to do my own delivery and the only persistently difficult provider is Microsoft’s free email offerings which I care about about as much as they care about running a reliable mail system for their users. They seem to penalize infrequent low volume senders. I have always been signed up to their spam monitoring bullshit and have never had a negative report but they don’t seem to communicate there so you can be blocked and nobody knows how or why. They blocked most of my hosting provider once so I routed my outgoing email with correct dkim, spf etc from a server hosted elsewhere. Easy to do with Postfix.