I've developed a fair share of failed apps the last years. None of these has gotten any traction. Instead they have just died, sooner or later. Why? Well, either nobody wanted them or I was lousy marketing them or even gave up too early.
Either way, building an app that no one uses isn't all that bad. Even if you're not building for yourself you still learn a lot by just building. At least for me I think that the building is what drives me and makes me come back for more. Of course, it would be fun if someone used it. I mean just creating something that another person needs and loves using, that's amazing right there.
One of the most important things about building that I've learnt is that if you're building something for yourself or making something that you're passionate about, traction or not, you will always come out a winner.
So keep building, these are amazing time