I started learning rotations, translations, scaling, shears using matrices in high school.

Affine transforms are apparently attributed to Mobius and Gauss. That’s like the 1700s.

What is vector based 2D graphics if not a direct application of geometry? Were we not using well known maths results when 2D graphics was first implemented on a computer?

> What is vector based 2D graphics if not a direct application of geometry? Were we not using well known maths results when 2D graphics was first implemented on a computer?

We were, but in high school, they aren't teaching you computer graphics, they're teaching you how to apply weirdly specific rules to transform some scribbles into more scribbles, for no good reason - hence the common student question, "what will I ever need that for?".

FWIW, I actually got into gamedev as a hobby as a kid, and it saved my life prospects, because it gave me a reason to be interested in trigonometry and algebra - all those random scribble transformation rules were directly applicable to problems relevant to me, such as "how do I rotate the bitmaps that are spaceships and rockets and turrets?", and such.

Nearly all modern 2D graphics systems are modeled after PostScript, including PDF, SVG, Java's Graphics2D, etc. In fact, Adobe employees contributed to the specifications of those technologies. Based on that I'd say PostScript popularized it. Other 2D graphics libs such as X-Windows, AWT, Windows GDI, Apple QuickDraw etc. didn't support transformation matrices. Maybe they never heard about Mobius and Gauss?