No need for that. While it's possible to point out particular "performance" car CVTs that do indeed compromise efficiency for aesthetics, that's not done in most cases, at least not to the degree that efficiency is significantly compromised. The actual reason for not doing as suggested and placing the entire burden of acceleration on the CVT (thus keeping the engine at a constant RPM) is that this would be a foolish design.
Between the precision electronic fuel delivery and ignition, variable valve timing, variable plenums and other features of your ICE, all of which are invariably present today when an ICE is the prime mover, the ICE power curve has wide RPM bands in which its efficiency is high. By taking advantage of these wide bands of efficiency, the CVT can have less size, mass, mechanical loss, cost, etc., than would be the case if the CVT were required to precisely enforce a constant engine RPM.
Minimizing the burden on the CVT is crucial because CVTs are a mechanical compromise: they are inherently not as strong as a conventional transmission and generally have higher mechanical losses.
The manufacturers responsible for these designs aren't actually fools, slavishly beholden to some old fashioned transmission aesthetic. They're responding to a large number of pressures and doing the math. The math says that constraining the ICE to an efficient, yet non-zero, RPM band is better than trying to manufacture miraculously agile CVTs.
Between the precision electronic fuel delivery and ignition, variable valve timing, variable plenums and other features of your ICE, all of which are invariably present today when an ICE is the prime mover, the ICE power curve has wide RPM bands in which its efficiency is high. By taking advantage of these wide bands of efficiency, the CVT can have less size, mass, mechanical loss, cost, etc., than would be the case if the CVT were required to precisely enforce a constant engine RPM.
Minimizing the burden on the CVT is crucial because CVTs are a mechanical compromise: they are inherently not as strong as a conventional transmission and generally have higher mechanical losses.
The manufacturers responsible for these designs aren't actually fools, slavishly beholden to some old fashioned transmission aesthetic. They're responding to a large number of pressures and doing the math. The math says that constraining the ICE to an efficient, yet non-zero, RPM band is better than trying to manufacture miraculously agile CVTs.