Some buildings or warehouse condos that you may rent or buy might not allow you to install the proper drainage system; which puts you at risk of flooding your neighbor businesses.
The slope aids in NOT soaking the rug in its own filthy water with a flat blow up rug pit and water removal is better.
With that said-- I guess a "Cadillac upgrade" to the system would be to put it on hydrolics so that the pitch can be changed from flat to sloped.
this way the rugs could be sloped if soaking is desired-- but Then there is the washtub for that.
We have a concrete washpit now, but in previous premises we had a sloped platform made from plywood with liner. If doing again I would construct one so that it could be put up on side when not in use to save space.