The Economy of Language

Jeffrey Lee designed Impact in the mid-1960s, when there was a renaissance for bold, condensed typefaces. The Schmalfett Grotisk font had been drawn by Walter Hötzenschweiler and because Impact was less condensed than this other font, designers often used these two fonts together. Nowadays, fellow ridiculous historians, you see it in memes. It's the default font for things like caption meme. And developers use Impact because it's super readable.