Long-distance energy transfer without energy loss will make it possible to connect more energy grids and sources together, so stuff like the saharan desert providing solar power to Europe, for example, suddenly becomes feasible. Maglev trains will no longer require lots of power to run, since they could utilize superconductor magnetic levitation. You could make super-efficient processors that wouldn’t really heat up at all. Superconductors are also key to quantum computers, so expect lots of advancements in that field as well. They will also make it much easier to build and run fusion power experiments.
Lots of tech in general would benefit from this discovery, stuff like MRIs, electric vehicles, space telescopes or particle accelerators would become way more efficient, cheaper and easier to produce.
Edit: also, check out this video by Isaac Arthur for some more sci-fi examples of what this tech can be used for in the future (discussed in the second half). It’s more space-colonization-focused and kinda like a thought experiment, but interesting nonetheless.