[nopinsight]

Rule-based NLP has been tried for several decades and has (very) limited success in the real world. Current systems based on deep learning beat it for most complex tasks. DeepL, which was on HN front page a few days, is the latest example: https://news.ycombinator.com/item?id=15122764

[orthoganol]

You're going to have to elaborate on complex tasks. I would argue the majority of successful, money generating software based in NLP/ NLU, i.e. the majority of the industry, is "rule based" (used in a general sense to mean non DL). Personal assistants, search, chatbots, etc.