[deltron3030]

If you're part of a community where people do things in a similar way, like a shared culture, you will discover pain points that aren't adressed by anyone, that you can solve for yourself, and if it works for you and you're not too exotic in the way you work (that's the side effect of a shared culture), chances are that it works for others as well.

So you validate it based on adressing your own pain points. The worst case scenario is that you were wrong about the exoticness of your workflow, or the actual size of your community and culture, and keep being the only user. But it's still not a failure if it helps you with your main work.