Why would anyone want class AB amp when class A always sounds better ?

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. 

Just buy whatever sounds best to you..  Glad we have choices..
I will stick with Class A amps as they provide the best sound to my ears. I agree with @atmasphere , The topology is simpler, but requires a better PS and ways to manage heat. Those who buy based on efficiency alone are missing out..

I might be off here, but class A amps don’t drive lower impedance speakers very well either. Most class A amps aren’t stable into 2 ohm loads. Krell being one Of the exceptions.

I might be off here, but class A amps don’t drive lower impedance speakers very well either. Most class A amps aren’t stable into 2 ohm loads. Krell being one Of the exceptions.

Sorry your off, one word for both, no.

Cheers George

Big Boulder and Gryphon are stable down to negative impedance. Oops, slight exaggeration, but I was close. Down to 1 ohm, I think.