I don't agree: the fix is hard, because not only do you have to pick one of the many at-war non-standard standards for your links in JSON, but then clients must

I don't agree: the fix is hard, because not only do you have to pick one of the many at-war non-standard standards for your links in JSON, but then clients must figure out how to interpret the links. I think the empirical evidence of the last two decades overwhelmingly supports this conclusion. This is what HTML gives developers: they don't even realize they are satisfying the HATEOAS constraint because it is simply so natural.