Netlify is exactly that with Gatsby, I have two blogs running on them.
Many themes have now deploy to Netlify buttons:
https://github.com/netlify-templates/gatsby-starter-netlify-...
Many themes support https://www.contentful.com/ as a backend.
The only thing that's a little concerning to me is the separation of domains: Hosting on a freemium service which deploys me a Node/React based static site generator that can connect to a third party headless CMS. That's why I still use markdown as the source of the content.
Too many moving parts, but at the same time if one goes down for good, I can fix it quite easily.