Worth it for me. I have the freedom of hosting as many domains, accounts, and aliases but no extra charges. If you only have yourself, simple needs, and care less about holding your own data, maybe it is not worth it. It all depends.
I also would not say it is “easy”. It is if you already know what to do, but you can say that about a lot of things. And mailcow makes it all “easier”, but when something breaks, it is often not at the best time to figure things out.
I get less spam on this setup then I did with Google. I owe much of that to greylisting, which is very effective, but not everyone’s cup of tea.
My biggest problem over the years is delivery failure due to various written and unwritten rules. Some people here will say you just have to have a clean IP, but it is NOT that simple when dealing with Google and MS. In the end, I use Sendgrid for my outgoing. We send so little mail, we will always be in their free tier. I’d rather not use them, but it is better than giving up on selfhosting for me.
And finally, if you are not going to bake in backup and recovery into your plans, don’t bother. Make that aspect of your buildout equally important.
But, that assumes that it is the same time horizon as what we experience. I’ve often thought of the scenario where we are living on something that is like a quark of an atom of a much larger existence. And that maybe we make up a small bit of a dude who is sitting around having similar thoughts. But, this enormous (to us) dude moves on an extremely slower timeline. So slow that they there is no possible way we could communicate, even if either of us realized. And in the same regard, there are whole worlds that exist inside the quarks that make up the atoms that make up us. Maybe it is even a recursive existence that goes on to infinity. Because, why not? Prove me wrong. :-)