[D] Current state of Chatbot pipelines in Commercial settings?

Hi everyone, I'm currently tasked with researching pipelines to build local custom Chatbot for my university. I have been reading about approaches like RAG, Rasa, Dialogflow and specific pipelines such as LangChain, Ragflow, KRAGEN and had some results from testing. However I want to capture the current state of which pipelines and approaches are most effective for building a Chatbot, especially in commercial settings. I'd be really thankful for your all information!

build chatbot commercial current dialogflow however langchain machinelearning pipelines rag rasa reading results state testing university