The introduction of advanced 
Natural Language Processing (NLP) and 
Machine Learning has caused a paradigm SHIFT in the effectiveness of chatbots. As discussed in sources like 
Fierce Healthcare, modern chatbots can be trained using vast datasets to understand context, intent, & nuances in user queries. The evolution reached a critical juncture with the deployment of models like OpenAI's 
GPT-3 and 
BERT, making it possible for chatbots to learn from experiences rather than relying solely on scripted responses.