Build what and for whom? Building / coding is not the gating factor or important thing here. We can pretty much build anything, right? For me finding customers

Build what and for whom? Building / coding is not the gating factor or important thing here. We can pretty much build anything, right? For me finding customers and problems to solve for those customers is the most important first step. I can build something, but unless I have paying customers what good would it do other than for learning / doing sake?