Some will say that the greater tube length allows for the choke to be cut with a geometry helpful to patterns, ie forcing cone and parallell section, for example.
As some claimed the chokes cut by Becker in the old Foxes resulted in superior patterns.
I'm guessing that clays shooters looking for ease and identification drove a lot of the interest, as did turkey hunters looking for any way to funnel ever more shot down a barrel to kill a turkey ever farther away....or duck hunters and non-tox.
I'd also guess that wad design and all the other particulars in a load are of equal importance, at times.
But, it is both easier to market and buy extended choke tubes than work on the specs within a shell or shoot better at the proper time and distance.....an extended tube makes you look professional and deadly as well....much like an AR.
Do they work as advertised?
I would say yes, with certain loads and certainly for the non-shot aspects of their use.
Worth the cartage tho?....not so sure.
Money often rated as hard to come by and harder to release seems very easily spent for this manner of product.
Justification and rationalization come easy to us all, one time or another.