Besides IPE, there is also Asymptote. (
https://asymptote.sourceforge.io/)
I think the lack of uptake is due to inertia. It takes a lot of effort to get up to speed with any system, so you are most likely to start with and stay with whatever people you know are already using, which seems to usually be TikZ.
For just the occasional illustration, it's easier to make do with something like Inkscape. (https://castel.dev/post/lecture-notes-2/)