@lrreynolds thank you for your note. I'm planning to write about this very problem in this week's issue of #TheFutureIsFederated.
I actually used Substack for 1+ year and moved my newsletters away in Jan 2024 when its owners refused to remove or demonetize Nazi content.
There is evidence that VC-backed Substack is on the highway to enshittification. An interesting read: https://radoncnotes.com/2024/09/26/enshittification-of-substack/
The pivot to video reminds me of how Facebook did the same with publishers - and it didn't go well