Eyeing a newsletter passion project

I'd like to start a newsletter to create side income and scratch a creative-curiosity itch. Thinking Substack but might also try Revue.

These subjects may not add value to indie hackers' pursuits but I've been writing too long on the creator economy to not try monetizing a project. I'd like to write about something I'm passionate about, hence the ideas below.

Any thoughts on platforms or tips for newsletter passion projects? While I've been writing professionally for years, I've never gone indie with it. I know I have a lot to learn!