I think the niche for chatbots is in working with existing customers/users. Unlike a website, a chatbot is not (typically) going to attract new customers/users. Nor is a chatbot likely to provide entertainment or general information. More or less a chatbot is useful for getting 'work' done and not really for entertainment/leisure. Yeah sure there are entertaining chatbots on Slack, but the context for Slack is mostly work.

But I could be wrong.