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

Class A amplifiers don’t always sound better. It depends on the headphones or speakers you’re using. Headphones and speakers with superior transient response (able to keep up with and resolve complex music) tend to sound better with Class A. But not all are made equal. This means you could have a Class A amp that performs worse than a Class AB - although, if designed well and without compromises, Class A is the gold standard.

This is a great resource:
https://circuitdigest.com/tutorial/classes-of-power-amplifier-explained

I recently added a Gustard X26 Pro to my Benchmark HPA4 | AHB2 mono. It replaced the Benchmark DAC3B (still keeping it). The sound of my system was transformed to that of the Gustard. The HPA4 and AHB2 do not seem to add any flavor.

It’s the ultimate chameleon. What the source puts in is exactly what the AHB2 dishes out. 

You're not going to operate Class A on solar panels and it is the opposite of going green. What it can be when properly designed is a fabulous sound that's very involving, Hey folks all Class A aren't created equal, just like Class D or Class AB for that matter.

No, this is not going green at all. I would personally compensate with other things, and others could too.
So, with less than capable speakers and headphones class AB can sound better ? Even if we are talking about excellent class A amp ?

So, with less than capable speakers and headphones class AB can sound better ? Even if we are talking about excellent class A amp ?

Who’s saying this rubbish, you get rid of transistor Class-B xover distortion when you bias higher into Class-A so long as everything else is unstressed.
Unless xover distortion is liked🤦‍♂️🤦‍♂️🤦‍♂️🤦‍♂️

Cheers George