Binary was a poor choice of words I guess.

My point was that if the current material only supports very low current densities at this high temperature, then that restricts the use-cases for it. I feel much of the popular science press makes it sound like all superconductors are equal, apart from the critical temperature.

Ah, yes. If superconductors were actual magic and had infinite current and magnetic field capacities our society would look pretty different right now. :)