Interesting question that I doubt anybody will give you a straight answer to.

Keep in mind that most, or all frames are assembled in pieces that are epoxied together. And I don't believe the epoxy joints are failing, at least with carbon/carbon joints . Carbon/metal joints are more prone to failure.

So, in general structure, there may not be a great difference between a tube and lug constructed frame like a Colnago C40/C50/C60 or Parley and the monoque construction used by many other manufacturers.

Perhaps the greatest difference is shaped tubes allowing engineers to put weight and strength where they think it is needed, not where it isn't needed. Which is good in theory.