So I spent some more time reading through using HOCs in React and I think I'll have to give functional components more of a try. The specific example I was thinking of is https://github.com/graphql/graphiql/blob/50674292c55eadf0e61... but this component will probably always be complex because of the Codemirror interaction.
Ah yeah, that does take a while to unpack. I think a lot of the complexity there is dealing with a non-react library and the dynamic import(s). Binding non-react libraries can be a bit rough.
React functional components are not supposed to be complex. It's easier to split FCs up than in Vue for example. Even React's class based components discourage splitting components by adding more boilerplate.