Your web browser may have also spent some time packing rectangles into rectangles. I recall reading this article a while back about how Firefox does/did it.
https://mozillagfx.wordpress.com/2021/02/04/improving-textur...
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.