G-code is indeed an old language, but it's the industry standard because it's better than all of the alternatives. There are complex G-codes, such as threading

G-code is indeed an old language, but it's the industry standard because it's better than all of the alternatives. There are complex G-codes, such as threading, which allows you to define the pitch, thread depth, cutting style, the distance to move away from the material between passes the distance to cut the thread, etc. But a lot of G-code files do consist of thousands of discrete lines. The reduction of a 3d shape to motor signals will eventually come to a stage that deals with lots discrete vectors, regardless of how you represent the data, G-code or not. G-code files consisting of thousands of lines are usually created by a CAM software anyways, not by hand. Your strawman argument of a 10mm bit when only a 5mm bit is available extends to just about any type of standardized process that consists of instructions being evaluated.