Ask HN: Why Poetry did not become a mainstream package manager for Python?

I have recently been introduced to Poetry. I am a pretty experienced Python dev with both back-end and ML in my project basket. However, I have been using pip/requirements.txt/setup.py so far for every single project I had done. But once I have tried Poetry, I do not think I will ever go back.

I was wondering why is it not more popular? What is holding it back? What do you think?