What exactly is critical listening? Who does it?

Your question is surprising, given how many times I’ve seen you on the forum. You express a common misconception about critical listening. It’s not about habitually listening in a way that is always dissecting every single instrument or constantly evaluating every sonic aspect. That would indeed be exhausting and detract from enjoyment.

Critical listening is best understood as "listening with a specific, often temporary, goal in mind for system improvement." Think of it like this:

Imagine your audio system is a garage. You don't reorganize it all the time; you do it when you need to. At the beginning; when you've added a lot more stuff to it; when you've changed things around in it or have different priorities. You don't reorganize a garage most of the time. You just use it for other purposes.

Same with an audio system: sometimes, you need to "critically listen" to set it up  or re-organize it. You might focus on a particular section (e.g., the bass response), identify what’s out of place (e.g., boomy bass), and make adjustments (e.g., move the subwoofer). This is a focused task with an end goal: a better-organized garage.

Once your "garage" (your audio system) is optimized to your satisfaction – perhaps the bass is now tight and well-defined, or the vocals are clear and present – you don’t need to keep "re-organizing" it. You simply enjoy the improved space.

Who does critical listening? Well, anyone seeking to improve their audio experience. This could be audiophiles, audio engineers, or even casual listeners who notice something isn’t quite right and want to fix it.

Does it bring enjoyment? Some enjoy the process of analysis. Others -- it sounds like you -- find thinking analytically to be irritating or difficult and not pleasurable at all. To each their own. But in either case the *outcome* is a more satisfying listening experience. Once you’ve addressed the issues, you simply relax and enjoy the music without your brain nagging you about imperfections. It’s about getting to a point where the "quality of what you’re listening to" sounds good enough so you can stop being critical and just appreciate the music. 

majority of folks I have noticed audition gear and trade alot to other brands chasing that nirvana, I think its more hobby to them than to enjoy and listen.  I bought what I consider the best and I like to sit down and listen to the most accurate sound I can, imagine want imaging to be the best it can and I want voices and instruments to be as natural as possible, I look for resolution, dynamics and control

Critical listening is necessary if one is to progress, also necessary to have a knowledge base/listening encyclopedia in order to obtain a reference or references as a goal. I spent far larger percentage of listening time in critical listening mode to my systems and others in early years, decades. Over time as I've come closer to my goals, far less time spent in this mode, mostly I admire the sound if I do go into this mode. 

Critical listening mode shouldn't always be seen in a negative light, it is a necessary tool in the audiophile tool bag.

Critical listening means optimizing the setup and listening closely to what the system is doing. 

The MORE effective critical listening must happen in more understanding of audio sounds because our ears trick us. All audio systems (incl. million $ systems) sound/behave veiled & distorted like speakers below. 

Listen to spkr sounds. Not Jay’s voice.

Your audio system sounds like the left speaker

Alex/Wavetouch audio

Maybe it’s like going to a museum and looking at a painting done by a master. For many just visually looking at it, it achieves lots of enjoyment. And then for others, they understand all the work related to color choices, brushing techniques, contrasting, depth perception - they put a lot of thought in looking at the Picture because they understand what it’s all about.  Most mere mortals have no clue.

Many of us mere mortals may wish we better understood all that goes into the picture which no doubt would allow a better appreciation for all it took to achieve it.

There are some remarkable paintings in this world and I wish I would’ve taken some art classes in college.