Crossover is the commercial version of the code behind proton, developed by the same company. It doesn’t work as well on Mac as on Linux. Since “Like Linux but worse” is exactly the point you’re responding to, so you’re pretty much in agreement with them?
MSFS implements optimizations on top of that (progressive detail, compression, etc), but that’s how almost all map systems work under the hood. It’s actually an efficient way to represent real environments where you don’t have the luxury of procedural generation.