This is not truth, just author is too young. In real life, in 1980s, when appear first Laser printers, some of them was "software driven", and used special sof

This is not truth, just author is too young. In real life, in 1980s, when appear first Laser printers, some of them was "software driven", and used special software on computer to render. And one of example of such "software printer" marketed by Sun, and I know exactly, their software stack was very agile, so people connected Ghostscript instead of standard proprietary render engine. Other parts are similar to 3D printers slice engines. Also, render is not simple task, so even when have "hardware" render board, in HP LJ 4M, we always use "dither by software" switch in Photoshop in 90s, because much better quality and lot more properties to tune accessible, vs "hardware" render board. So, reason is the same, why Photoshop exceeds GIMP - just too much work need to make really good software, but nobody will sell hardware for it, so modern 3D printers ecosystem (with open firmware), appear just because Chinese dumping hardware sales, so appear niche for opensource 3D printing solutions.