Well....
Most people who get a bit dedicated about their riding do tend to buy cycling jerseys fairly soon. And the elasticated pockets at the small of your back that those jerseys have are pretty well proven in their design and functionality. Admittedly though, different makes do it differently well.
For frontal access there are neat little cases that strap on to the top tube, just behind the stem.
If I'm on a longer ride, odds are I'll be carrying either a small backpack or a camelbak. Then I already have a pair of shoulder straps available that I can clip pockets and pouches to. And by now, I have quite a selection of those.
If it's a backpack, there'll be a waistband too.
But sure, If I didn't already have that selection of pouches, then your design would look rather inviting.
Right now, what would be my most probable "window of opportunity" for usage would be while kayaking. The pockets sewn onto the front of the floatation vests are ridiculously tight, and something that could take some more volume could come in handy.
Or possibly jogging - assuming that stuff carried on your chest doesn't bounce as much as a ***** pack does.