I think the effect is almost even more pronounced if you go in the other direction and look at a 1D space, i.e. the real line. Then both a sphere with radius 1

I think the effect is almost even more pronounced if you go in the other direction and look at a 1D space, i.e. the real line. Then both a sphere with radius 1 and a box with side length 2 will become the same interval, with no difference. In the OP setup, the middle sphere would vanish completely and (modulo some annoyances at the interval boundaries) become either the empty set or a single-element set, in either case having both radius and volume of zero.