Most STT systems also tend to still train on normalized text which is free of the punctuation and capitalization complexities and other content you find in text

Most STT systems also tend to still train on normalized text which is free of the punctuation and capitalization complexities and other content you find in text LLMs. I suspect we continue in this way in part due to lack of large scale resources for training, and due to quality issues - Whisper being an outlier here. Anecdotally 8bit quantization of larger pre-normalized STT models seems to not suffer the same degradation you see with LLMs but I can't speak to whether that's due to this issue.