The promise of REST and HATEOAS was best realized not by building RESTful apps like say "my airline reservation app" but by building a programming system, spiritually like HTTP + HTML, in which you'd able to declaratively specify applications, of which "my airline reservation app" could be one and "my sports gambling service" could be another. So some smart person would invent a new application protocol with rich semantics as you did above, and a new type of user agent installed on desktops understands how to present them to the user, and the app on the server just assembles the resources in this rich format, directing users to their choices through the states of hte program.

So that never got done (because it's complex) and people started building apps like "my airline reservation app" but then realized to to build that domain app you don't need all the abstraction of a full REST system.