I can't speak for this other app, but one thing that differs us from other Personal CRMs is our emphasis on data privacy. The team here is pretty obsessed with security and data privacy, and we created an app focused on those values.
I see where you're coming from, Masonic. Having an open-source product would add a layer of trust, especially if you host it yourself. However, there are people who would not want to go through the hassle of self hosting, and we believe that these people deserve a commitment to privacy too. With UpHabit, we created an inclusive app that while hosted on our own servers, come with our promise that we’ll never sell user data.
[0]: https://github.com/monicahq/monica/