I wonder if folks that like mailing lists (that's still a thing that some folk like btw) would appreciate lists being on open source, privacy focused stuff like listmonk/discourse/whatever or if they prefer centralized, closed source systems like mailchimp.

or if it doesn't matter and it's simply a value call (and devops cost) for people that manage lists -- like "I have the choice, so why would I subject my readers/subscribers to mailchimp privacy concerns?"