The knapsack problem gets much harder as you increase the dimensions.
Placing parts on a PCB is harder if you have to care about where the components go relative to each other (e.g. because they have to be electrically connected, a certain distance from ink marking or drill holes, due to thermal or interference issues etc) rather than just optimizing space used.
I had this guy as a prof. https://en.wikipedia.org/wiki/David_A._Klarner I have never encountered someone so excited about dividing up rectangles, as it is related to combinatorics. Also with such a seething hatred for floating point numbers.
I guess it's not really that necessary now that most sites load 25MB of JavaScript and a 250MB video that plays onload.
https://mozillagfx.wordpress.com/2021/02/04/improving-textur...
Plus there are a fair few programs that render text by rendering the font into a texture atlas once and then using the GPU to copy from the atlas. Your terminal emulator may be doing this, for example.