It's a tricky problem indeed, this one regarding their app, although not a surprising one. Last month, Hamish McKenzie (cofounder) wrote[1] that “the trend that Substack is part of is not a newsletter trend, or even the much-hyped creator economy”. So, an app that distance subscribers from e-mail was expected.

Btw, giving a special address would increase the lock-in, IMHO. The newsletter owner would be dependent of Substacks benevolence forever.

As I wrote, I recognize Substack as a force for good, but there are cracks in their promise and considering it's a VC-backed startup, things only tend to get worse in the long run.

[1] https://on.substack.com/p/please-stop-calling-it-the-newslet...