You are ignoring the advances in SC materials over the past few years.
This is certainly true. The last time I looked they were getting superconductivity in materials a bit above liquid nitrogen. That's still pretty cold. I'm sure they are doing better now.
Back when I was just a young engineer we were using lead (yes just plain old ordinary lead) as a superconductor to provide a magnetic shield for a cryogenic ruby maser. That required liquid helium temperatures but that was OK since that was the temperature (a few degrees Kelvin) required for the maser itself.