E-mail was the first "thing" that got me off of Google (to Proton & then currently Tutanota) but is really the last remaining service I not have self hosted.
I have always read about how difficult and time consuimg it was to run your own mail server, but I felt like I needed to experience it myself. So I purchased another domain and followed the instructions on https://mailinabox.email/.
I am using a small VPS on Hetzner and I have to say the experience has been almost flawless so far. I did need to have my new domain taken off the Domain Block List, but Hetzner gave me a clean IP and defaults to blocking port 25 outbound to prevent spam (simple ticket to open, once account is 30 days old and paid).
I know I'm still early into this journey so far, but it has been really simple and I plan to test this secondary domain for a few months before moving onto it full time.
As an avid self hosted of literally everything else, I can say it has been a lot of fun learning so far!
Yes I haven't had any real issues with Tutanota, but it seems like the common trend is that they, and everyone else, is raising prices for things I dont really need. But at the same time, the things I do need, I.e. accounts with enough storage for my family, will start costing more than the price of renting a VPS alone. So for me, its partially privacy, but also ownership of my data and cost benefit analysis where I am now trying to make CERTAIN that my self hosted email is worth the cost savings.