Although Class D is the first amplifier topology that theoretically offers completely linear operation with 0% distortion and no power loss at 100% power efficiency, the commercialization of Class D audio amplifiers had to wait until the ‘90s when silicon (Si) MOSFETs with sufficiently good device parameters became widely available.
https://www.powerelectronicsnews.com/opening-up-the-next-chapter-of-class-d-audio-amplifier-performa...
I saw theoretical max in the post.
Since this is all subjective I wouldn't trade classD for classA as long as each amp were designed properly and were used within their parameters.