"But the reason Substack wants you to call your creative work by their brand name is because they control your audience and distribution, and they want to own your content and voice, too. You may not think you care about that today, but you will when you see what they want to do with it."
https://www.anildash.com/2024/11/19/dont-call-it-a-substack/
Kudos @anildash for this and yes, any sane person should move away from it before it's too late.