There’s a pretty rich landscape of FOSS+SaaS type WYSIWYG editors out there. Aimed at being a either the complete package like Wordpress and Ghost or even some that try to integrate with your current stack (a backend but you provide the frontend), like ContentStack and Sanity or Payload. Even some strange inbetween providers that have features like “generate React component from figma design and import it into your codebase via copy/paste”, like builder.io.

All of them and none of them. Because really we're talking about serving pages from content fragments in a SQL database, with a style separation and dynamic content constructs.

It's not a radical idea; you can write your own thing that does only what you need it to, and that is an entirely appropriate way forward.

You will end up solving a bunch of problems quite like WordPress does.

All CMSes are at some level like WordPress, and yet there is nothing like WordPress. Because it's not about the application, it's about the tradition and ecosystem around the application.

Ghost, but only if your primary focus is blogging (rather than a CMS or e-commerce platform).

check out Craft CMS