Why isn't RethinkDB more widely used?

RethinkDB was a popular NoSQL database in the early 2010s, known for its real-time capabilities and ease of use. However, its popularity declined after the company behind it shut down in 2016. The main reasons for this decline include the competitive landscape of NoSQL databases, the lack of a clear business model, and the challenges of competing with established players like MongoDB. Despite this, RethinkDB's open-source project continues to be maintained by the community.