It is. So my advice is to build something that is interesting, and might have some value, and don't worry about it being financially viable. Then get it out there, iterate, pivot, learn and eventually you may find viability.

My point is, more often than not, there isn't a eureka moment when a fully fleshed out idea with financial viability just pops in your head. Oftentimes the best ideas start out small and boring. Use your day job as the de facto funder of your quest for viability.