The process begins with the Refinery extracting a giant portion of a target planet’s surface and bringing it to space. That chunk is then broken up to create a small asteroid field near the refinery, which players can mine to get precious materials.
Okay, clearly someone skipped both physics and geology. It would take a tremendous amount of energy to "extract a giant portion of the target planet's surface and bring it into space".
Second, the valuable materials tend to sink to planets' cores. Whereas, if you mine existing asteroids and comets, the density of heavy elements is probably far higher.
Finally, there's no way that extracting a giant chunk of a planet isn't going to create all sorts of orbital debris.
So, it would be far cheaper, easier, safer, and more profitable to mine one of the vast number of asteroids already out there. That's why companies and governments are trying to do exactly that.
Dumb game.