Comment by incorporeal

Seconding that that one stood out to me. Actually studying at-least large portions of it is typical at a handful of liberal arts colleges that favor the "great books" approach, at least a couple of which have pretty good reputations and are likely to have turned out some folks who work in tech (maybe the programmer next to you... maybe your manager's manager), plus it's pushed in great books home learning programs that surely at least a fair number of people have credibly attempted, even if the overwhelming majority of those who start such programs don't complete them (and it's usually very early in those programs, so even those who gave it a real shot but abandoned it before getting far were likely exposed to quite a bit of Euclid, though maybe they dropped off before On Conic Sections or other texts common in those reading sequences).

... plus it's relatively approachable as such things go, and short enough that closely reading most or all of it isn't a crazy idea, and it was recently-enough widely used as an actual textbook that between that and ongoing modern interest in its use in that capacity, there are tons of study-oriented editions of it floating around and still being published. I mean hell "recreational mathematics" is a thing and lightly-annotated-and-updated Euclid's a pretty solid text for people with that kind of interest to noodle on, with bonus historical appeal since it's super-old and also is assumed background for all educated people into at least the early 20th century, so pops up all the time in historical writing and literature.

Now, Newton? That's more like it. Nobody reads a large amount of his mathematics unless they're some variety of mathematical historian.