Hello! I agree with all of the above. Just pointing out as I was researching this matter recently for my woman: this good old (and clunky) wordpress also does the job. Wordpress + jetpack plugin if self-hosted (really easy with many hosting providers) for automatic newsletters and monetization (all integrated on wordpress.com) Other alternatives if needed:

How to Leave Substack.

You Should Probably Leave Substack

You should probably leave Substack. Here’s why and how.