I think that’s an interesting alternative, but one of the issues arising would be the dichotomy between “maths mode” graphics and “computer graphics mode” graphics. Plots.jl enables “maths mode” (origin at the centre, y-axis up the page, unit circle fills the screen, etc), whereas Luxor imposes “computer graphics mode”: a 1-unit circle drawn in Luxor would draw a tiny pixel-or-two at the top left of the screen, and moving 5 units in y would move that pixel-or-two down the screen by 5 pixels or so. In other words, it would be necessary to “convert” the maths mode coordinates and conventions to computer graphics mode screen/PDF/PNG coordinates at some point. It’s simple enough, but requires a bit of extra work…
It’s possible to make maths-style diagrams like this of course. Here’s one I did in Luxor a few years ago: