High-quality conversational interfaces (chatbots and voice assistants) have traditionally been difficult and expensive to build. An effective chatbot requires Natural Language Processing/Understanding (NLP, NLU) and other Deep Learning techniques to understand the underlying intent of human language.
These techniques require skills that are difficult for individuals to acquire and expensive for organizations to hire. Even if you have the skillset at hand, the amount of conversation data required to build natural interactions is labor intensive and expensive to collect. Given these facts, building a chat interface for your application or product likely does not offer enough value for the cost. Until now.