Just let me add here that for applications in quantum computing the limiting factor is not the cooling required by the superconductor to function, but the more or less perfect isolation from environmental influences you need to keep the superposition of quantum states alive.

Regarding technical applications of high / room temperature superconductors, I've written this article (which incidentally has the same title image as yours): https://medium.com/age-of-awareness/why-dont-we-have-superconducting-power-grids-806fef018231