I could chime in on the "these big, wealthy companies are all stupid, they don't appreciate brilliant work and you should be glad they did not hire you", but then you might experience a similar situation next time again. Your choice is to acknowledge another weakness or repeat the situation. Here is an alternative view.
I do find that 30min is far too short to get a noiseless evaluation of candidates. Little things can trip even the most experienced coder and the pressure makes things worse.
However, Leetcode exercises coding, but not ML coding in particular. If you had been interested practicing on Kaggle, you would have undoubtedly known the Pandas shortcuts. They correctly, concluded that you had experience coding, but not as an all-rounder for ML and rather as a specialist for NLP. They may even have thought that you did not show interest in ML beyond your assigned work previously.
The attitude of doing "projects from scratch" and finding Pandas "shitty" hints that you may be over-engineering opinionated code and no company wants to pay coders who waste time and are opinionated about their work. Maybe the interviewer sensed that. Companies don't necessarily respond with all reasons why they rejected someone.
You may find all what I wrote BS, but if you don't consider it even the slightest bit, it confirms things I wrote and the next interviewer may sense that again.