This could be greatly simplified (at higher cost) by using linear motors for the cross-slides.
It may even be more rigid than what is there now (though nowhere near rigid enough to do anything real)
The design is actually not unique at all - you can buy much better versions of it (at higher cost, obviously).
Most positioning actuators you can buy are literally built to be attached to each other in a cross-slide configuration, and to have a rotary table attached to it. They also directly sell pre-built cross-slide actuators.
If you just google "cross-slide stepper" or "cross-slide servo", you can see this
(servo/stepper just gets rid of the manual ones, which also exist).
The normal reason the configuration is not used is because it has no meaningful rigidity.
It may even be more rigid than what is there now (though nowhere near rigid enough to do anything real)
The design is actually not unique at all - you can buy much better versions of it (at higher cost, obviously).
Most positioning actuators you can buy are literally built to be attached to each other in a cross-slide configuration, and to have a rotary table attached to it. They also directly sell pre-built cross-slide actuators.
If you just google "cross-slide stepper" or "cross-slide servo", you can see this (servo/stepper just gets rid of the manual ones, which also exist).
The normal reason the configuration is not used is because it has no meaningful rigidity.