There is one economy of scale which eventually hit the bespoke suit industry: robotics/automation. Eventually you will be able to make tailoring robots to do each step of the process, much like they do in car factories. With the proper software you could step into a booth, get a 3D body scan and have the suit finished in hours or minutes.
This may work for crude made to measure suits, but bespoke is often more about trial and error than incredibly precise measurement. It also has a lot to do with the preferences of the client, particularly with regards to the shoulders and armholes.
As for automation, a large number of MTM tailors currently email the measurements to a factory in Asia where the suit is cut by a worker getting paid pennies. The cost isnt necessarily in the making of the suit, its more the measuring and interactions between the tailor and the client that can take hours. For this reason alone I dont think we will see tailoring robots anytime soon.
