I hear this a lot but I think the point is moot. It kind of reminds me of communists telling me that real communism has never been tried.

Okay okay I know, analogies are sinful. Sorry! My point is that this pure definition of REST doesn't conflict with what the parent comment outlined. I'd go even further and say that to implement in this purer, Content-Type agnostic, state-evolution by hyperlinks kind of way makes the implementation even harder (around as hard as it is to implement a GraphQL endpoint).