Before the 32-bit era, game development tooling was very nonstandard, and a lot of studios rolled their own. For example, Sunsoft's NES graphics/animation software ran on the Famicom Disk System (Japanese-exclusive NES add-on that let the system run software from proprietary floppy disks) so they were absolutely optimizing for consumer TVs with rectangular pixels. https://www.youtube.com/watch?v=O8PR2EShp70
