Yes, it has. The problem is that nontrivial clothing requires multidimensional fit which is impractical for mass-produced off-the-rack clothing, and marketing of mass-produced clothes is therefore driven by all kinds of things, none of which is using the well-established standardization and quantification of fit, which is used only by people making bespoke clothing or altering off-the-rack clothes for specific individuals.
Of course, unless it is paired by on-demand alteration, 3D fitting doesn't really address that problem.
But its not meant to (though the for-the-public image may be that), its to deal with the problem that taking clothes to actual fitting rooms increases handling, damage, theft losses, and the resulting policing and remerchandising is a major source of labor requirements for shops.
For the Gap, the problem this hopes to solve, or at least mitigate, is “retail employees”.