It's certainly true that there are a lot of PDF renderers out there with subtle incompatibilities (and bugs), and also a lot of PDF files with subtle nonconformances. However, that doesn't seem like a good reason to not write a new PDF generator!

Instead, write a conformant one. Better, write one that not only conforms, but also isn't affected by any of the bugs in popular PDF renderers, by testing against all of them. Shawn Davis at LevelUp Research, working on the same DARPA project I'm currently on, has written the amazing SPARCLUR https://youtu.be/6I6E1N3CJzQ (no sound) https://github.com/levelupresearch/sparclur https://pypi.org/project/sparclur/ which will feed your test PDF to Ghostscript, MuPDF, PDFium, PDFMiner, Poppler, QPDF, Xpdf, and some other PDF engines, and compare the results. That way you can see not only if any of them produce errors and warnings, but also if they render it differently or extract different text from it. SPARCLUR is Apache-licensed, written in Python, and very well integrated with Jupyter.

(We've developed some other tools for this as well, but they're not as accessible.)

SPARCLUR doesn't test your PDF against Adobe's implementation, or for that matter Foxit, and I don't remember why.

But basically if you're going to generate PDF files you might as well feed them to SPARCLUR's Spotlight and automatically verify that they work identically, or near enough, in half a dozen independently implemented PDF renderers. Hopefully SPARCLUR will dramatically improve the software quality and compatibility of future PDF generators.