Not sure what you're saying here, YBCO and related materials become superconducting with liquid nitrogen temperatures
But my point was not about the old inventions, but about this new PCPOSOP material. Researchers claim an insane jump to -23C (maybe) superconductor which is highly suspicious on it's own. It's like some researchers will claim they have discovered some material with a melting point of +10000C at 1 atmosphere. Sure, maybe. But the fact that materials with melting points between +4000C and +10000C are missing is super suspicious.