Substack makes it simple for a writer to start a paid or free newsletter. Writers get a CMS built for publishing email newsletters, integrated payments through Stripe, and a website that can host free and subscriber-only content.
I've hosted workfutures.org on Substack, after experience with Patreon and Steady. A great experience so far, a month in.
Easy to set up/use, responsive team
Single tier of subscriptions