I wanted to add django but their issues aren't on github as they are using their own system. IMO an external issue tracker lead to a higher barrier to create new issues, so this isn't not necessary fair.
Also fastapi allows people to ask questions with the issues. On the 1000+ open issues, 826 are tagged as question.
It's hard to find a fair metric. Open/close ratio rewards older project with fluctuating/stable popularity. Fastapi popularity is still growing[0], so having some difficulties to work on issues is expected.
Pytorch, 8400
Pandas, 3400
Tensorflow, 2100
jupyter notebook, 2000
scikit-learn, 1500
pytest, 720
requests, 170
The outlier seem to be Flask.