LEO orbits have been practical for decades, but things like GPS use MEO.

MEO was the standard, until now, for reasons. First of all, there is higher drag in LEO orbits as you are passing through the thermo- or else exosphere. This means more energy (and therefore mass) is required to maintain the orbit. And the more mass, the more gravity is pulling on you (LEO gravity is nearly the same as on the surface - you’re falling, but you’re missing the planet… until you’re not).

SpaceX’s “revolutionary” idea was to let/make them deorbit, and to use the space freight program to replace them. Of course, this was possible before, and planned obsolescence is already an important part of designing satellites. However this is insanely expensive and is only practical long-term because SpaceX is already being paid to launch their rockets. And more importantly, the volume of the LEO surface is the lowest of all orbits… there is minimal space available, and anything traveling to a higher orbit must pass through it. So there is a real risk of Kessler syndrome, where debris makes it impossible to continue using the orbit. And the debris of concern is usually small so they stay in orbit longer. This debris comes from launches, collisions, and potentially deorbits.

SpaceX is the only group that has chosen to utilize LEO as a consumable that is inherently limited in nature. They externalized the cost of pollution to society due to operating in an under-regulated domain. Now regulators are scrambling to find solutions for orbital pollution - enacting rules requiring deorbiting, supporting efforts toward satellites that cleanup debris, and so on.

Whether these efforts will be enough and whether they will come to fruition quickly enough, I do not know. But I do know that the rocketry industry involves a lot of pollution, is growing into a significant GHG contributor, and depletes ozone in the atmosphere (the hole in the Antarctic is still estimated to be 50+ years from healing, and one 8 times larger was just discovered in the tropics).