I like the idea of Substack, but it bothers me that they only bestow a domain mapping if you have "compelling reasons and full commitment to the Substack model."[0] This should be a simple paid upgrade. What's the point of all their talk of independence if you're stuck on a Substack subdomain when the inevitable liquidity event happens?
You can export emails and migrate paying subscribers, but all your links still point to a domain someone else controls. I don't want to have to set up a redirector just to protect myself. That's the whole point of controlling the domain.
[0] https://twitter.com/SubstackInc/status/1167162063879192576
Their business model is paid newsletters, but you can start with only free emails that is basically a free blog+newsletter with zero technical distractions.
My shameless plug, I write irregularly about writing for developers: https://writingfordevelopers.substack.com
It is not about technical writing though, but written communication.