Is there no service that uses automation to make custom-fitted shoes yet? This seemed like such an obvious thing to me several years ago when 3d printing and the like started becoming a fad, and I figured there would be a startup that did it (or one of the big companies would work on it). But if anyone is doing it, I as a consumer haven't noticed yet. What gives?

I can't see cost being an issue - when you look at how shoe construction works, it should be straightforward to tweak the shoe shape for each shoe without significant increase in manufacturing cost.