Honest question: Where do people get this idea that they state so confidently, that it's "impossible" to run one's own mail server? Have they actually tried or

Honest question: Where do people get this idea that they state so confidently, that it's "impossible" to run one's own mail server? Have they actually tried or are they just repeating what they've heard? Counter-anecdote: I have run my own mail server for several years. I use it for all my email communication, and also send out daily emails to a couple of thousand subscribers[1] who are on all sorts of email providers. The "canary accounts" I have set up on all the big providers all seem to have their subscription messages delivered straight to the inbox just fine, though I should probably monitor this better somehow. [1] the Aphorism of the Day, https://www.aphorismsgalore.com/ https://www.aphorismsgalore.com/