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

Develop some awareness of the topic
https://www.electronics-tutorials.ws/amplifier/amplifier-classes.html

Dan D'Agostino also thinks distortion adds musicality to his amps.
https://www.youtube.com/watch?v=JW7fg_yfza4

The history of audio shows that you cannot make blanket assumptions on any product based on theory: There are too many variables to make any conclusion that class A is always sounds better than class AB. The results are aways dependent on the synergy between the amp, speakers, and room.

Basically you can say, all things being equal Class A sounds better, but all things are rarely equal are they?  I can't see myself owning anything other than a Class A triode wired tube amp but my setup is optimized for that style of amp.

Yes but take away blanket assumptions and there goes 80% of site content. Take away pure unsubstantiated blather and there'd be like three of us left all reading each other.