A few practical things that we need superconductors for which currently require very expensive cooling:

1) MRIs — could be way cheaper, smaller and more ubiquitous with room temperature superconductors 2) Maglev trains — superconducters expel a magnetic fields that can make things "levitate" (called the Meissner effect). Maglev trains have minimal friction and are incredibly energy-efficient. 3) Quantum computing — most designs require cooled superconductors. Room-temperature superconductors are a requirement for future portable quantum computers, or quantum chips that sit side-by-side in conventional computers

There's a ton more implications, just think about how everything from electric cars to smartphones was only possible due to modern batteries — that's the scale of technical innovations that could be built on this.