I'm working on a similar thing, but due to various problems I encountered (auto-grading, scheduling, guidance, ...) I have, for now, concentrated on making a curated collection of problems / exercises. It's not yet a generator but rather "one of each kind of problem".
The idea is that _any_ user-facing tool, whether an app, worksheet generator or whatever, will need something like this for content, so I'm making this available for free and hoping for others to build on top of it.
I'm sticking to university-level stuff because I feel that school-level, especially math, is over-saturated already.
Technically, it is currently built as a React app, but that is mostly me sticking to tools that get out of my way. Generating PDFs or Anki files should be relatively straightforward.
Nice! University-level math would be great. That is my end goal as well, but I probably won't get to that until the end of the year. I am focusing on lessons that my kids will use, then switch focus to ones that I will use. Do you have it hosted somewhere? Or can you add some details/screenshots to the readme?