When it comes to MBA enclosure it's likely the infill or separation problems with long thin walls that led them to abandon injection molding. Even then it's not done on a mill in one take. Things like speaker grilles are probably something like EDM or etching rather than 8000 operations with 0.2mm drill bit.

And as far as parlor ticks go this is not particularly impressive, compared to old ones like turning cube inside a cube on a lathe.