Advanced tech like MRI machines, maglev trains, and quantum computers all use superconductivity now, but are enormously bulky and expensive because they require extreme cooling using liquid helium (which is in short supply). Room temperature super conductors can dispense with all that, so instead of a quantum computer being the size and power draw of a refrigerator (because it is in fact mostly refrigerator) it could go in your wristwatch.
Superconductors also expel magnetic fields, which in practical terms means they repel magnets. And they only repel, without being attracted to magnets at all, like iron or the poles of other magnets. So you can use them for levitation. And because superconductors have zero resistance, if you put energy into a superconducting coil it stays there forever, just circling round and round the coil.
This LK-99 material people are talking about is an alloy of lead and copper, and it's not that difficult or expensive to make. The raw materials are fairly cheap, and the production involves heating it to hundreds of degrees centigrade for 24-48 hours, which is very easy to do in a lab and probably easy to do at industrial scale. Scientists don't understand the material very well yet, but if these discoveries are validated (as appears to be happening right now), then refining the manufacturing process is going to happen quite quickly because the payoffs and economic demand will be enormous.
People are comparing this to the invention of the transistor; I think a better comparison is the electrical lightbulb. It's going to change things massively, because any country will be able to manufacture this. You could manufacture this stuff at home, the equipment you need fits on a desk and costs only a few thousand $.
