You missed the part about how large software is.
I could (and probably have worked!) my entire professional life in domains you've never once caught a glimpse of using kit you wouldn't recognize. To me it's trivially obvious how to, say, debug an SPI bus timing problem where you might not even know what an SPI bus is without looking it up in Wikipedia first.
(I guarantee you that within 3m of you there are orders of magnitude more SPI connections than any form of encrypted connections.)
Now the only reason I know what end-to-end encryption is and why it's important is because I took a short break in my mainline career and worked on PKI for about six years. (I then ragequit commodity software and went back to actual software engineering, but that's a different story.) Had I not had that experience I could likely have made some guesses as to what E2EE entailed, but I certainly wouldn't have understood immediately why this was a critical feature.
Really, software is a FAR LARGER domain than you think. Hell, it's far larger than I think, probably, and I think it's ten times larger than you think. 😉