Well… the developers are self described students of the ages of 17 to 19.

Making a project just to learn is par per course. Chat… especially non federated chat isn’t really that hard to implement as a protocol. It’s the UX that’s hard to nail down, and if they can get it right it won’t matter if Matrix existed first.

This is actually a pretty strong reason. If your target is to build an app like this, getting distracted by a completely different technology which might or might not be more usable for some subproblem is the easiest way to loose interest. And without interest, the open source project is dead in the water.

It doesn't need to be a success for them to learn from the experience.