The long story short is that faster cables preserve signal integrity better, and that’s generally the result of either technology/design upgrades (shielding, different twist, etc), or tighter manufacturing tolerances.
High speed signals are more of a fuss as the speed goes up, and at some point things break when everything isn’t just right. The endpoint simply cannot distinguish between 0 and 1 enough anymore.
CCA has issues with longevity, signal integrity and even safety. The installation process of a cable is always going to be much more expensive than the cable itself, so cheaping out for not much difference at all is just not worth it.