It is hard to deny that many, many products today are of a quality incredibly better than what we had in the past. That however does not allow you to forget about some of the basic principles of design and manufacturing. Manufacturing tolerances of a CNC milled rib for sure are much, much better than that of a sheet metal and standard profile riveted rib 50 years ago. Hovever, if you assume those tolerances are zero today (just because it is all manufactured on CNC machines or by robots), reality will bite you from time to time. And composites is not known for especially tight tolerances...