Mainly the ease of use, flexibility and deep focus on RAG. I've been using it for over a year now and have built a myriad of client projects using it. Before that, building the applications was kind of a pain since you had to write everything from scratch to build a simple RAG application.
I've also used LangChain but found Llamaindex to have better documentation and abstractions for the RAG stuff I needed. Flowise I've found pretty good for quick MVPs but building more complex and custom stuff hasn't been as easy with it.
