Of course, it wasn’t always this complicated. I am an old millennial, old enough to remember that airplanes used to be boarded from back to front. People needing special assistance and first class got to board first, but after that, you filed in based on your row number. That’s all changed, for two reasons, both of which can be thought of as technological advancements of sorts.
One thing that happened was that airlines discovered that boarding by row in reverse numerical order, while intuitive, is one of the slowest possible ways to board an airplane, because people bunch up trying to use the same bins and squeeze into the same rows at once. Even boarding in a random order is about 30 percent faster than boarding the old-fashioned way.