@dean_palmer 

That is an interesting take you have! You should write a book hypothesizing on how no one will care to read it! For some reason...I find it appealing!

I suspect that many of the folks who routinely post here in this forum are loners. Not that they (we) are loners in life, but let's face it, no one cares about you as much as you should care about yourself. Self-esteem has a lot to do with this hobby and most folks don't realize that fact. You (we) are focused on either trying to get better sound, or are making attempts to help others get better sound..all with differing levels of prosperity and commitment. 

With that being said, we all need something - especially in these fraught and tumultuous times - to allow us to get away from fear, anger, mistrust, and varying emotional distress. Getting away to a listening position is a superb way to wallow in your own making - one that generally makes us all feel good about ourselves - so we have a lot in common with one another.

But as audiophiles, we live far and few between one another. Most of us do not have many supporting mechanisms in place with regards to this hobby. Yes, my wife sometimes applauds an upgrade or reacts positively to the music, but she has no idea of how intricately I deliberate over everything that has to do with what being an audiophile means. Although I will admit that her talk of me going "down the rabbit hole" when I started placing sound dampeners and deflectors on our basement walls did get my attention! (However, she did remark later at how good the dampeners sounded! lol). Ok, small victories serve us listening loners well..

I grapple with this hobby daily and all audiophiles find positive reinforcement from it, even if it means you did something wrong and perhaps, "failed". Those whom I subject to sound don't give a rats *** about sensitivity levels, gain, or detail. I catch myself when I talk tech to others whose face grows longer the more I speak..why bother? So, you are correct in stating that, "Once you realize nobody cares about what you bought, you'll be in a better place."  

I believe (I will write the prologue for your book!) that what you are inferring is intellectual humility. We all should view the world with the understanding that we know nothing and need to learn everything. That would serve many audiophiles well. Audiophiles should get over their need to post about something they refute as it is counterproductive to learning. I mean, if you can't hear a cable then how have you assessed or aggregated an opine on it? 

We are likely incredibly different people - judging from the large swaths of deleted posts! - beyond the scope of sound but we all share the same pride at what each, and others, have created. That is an important feeling of achievement that audiophiles chase after. The "good enough" abstract brought by the OP is generally always a couple of steps away from perfection.

Enjoy the journey! 

OP …”I’m just curious. When you arbitrarily upgrade your system every 7 years, do you hear a significant improvement each time?”

OMG, yes… enormous. Each generation has been such a huge jump. In fact, each component is a very real and substantial improvement.. It can take a year or two for me to do the upgrades. So, for instance I may start by the speakers or preamp… the jump is phenomenal. I spend enough time to get it broken in and appreciate the upgrade in itself before upgrading the next piece.

I a m not sure arbitrarily upgrade is quite right. It tends to be a function of my finances… although very subconscious. I enjoy my system and I think my subconscious keeps track of my finances close enough to tell me when, if I really stretch, I can make a substantial upgrade… which as I am sure you know, for me is to as a minimum double my investment in each component. When I in upgrade mode, virtually every spare minute is reading, evaluating, dropping by audio shops in towns I am flying through… switching into critical listening mode for a lot of the time. 
 

So, when compete, I have a system that is better in no small measure in every respect from its predecessor. I will say I have gotten better and better (yes, partly due to overall improvement of high end audio) at upgrading and the difference has become larger and larger with each upgrade. The last upgrade was definitely the very largest sound quality wise I have ever made. While the investment level was by far the largest, I feel that the ten years of season tickets to the symphony had significantly changed my goals and contributed to the success of this last upgrade. 

How good is good enough?

The answer/answerS aren't so utterly defined by the gear as they are defined by the room, + the actual recording.

Now if I had a room with bang on acoustics that was 18-20ft wide at the front wall and 26-28ft wide at the rear wall. 36-40ft long, with a coffered ceiling 14ft high, then the law of diminishing returns could run hog wild.

One could justify up grading that Denon DL-103R cartridge for a Dynavector TE Kaitora, because in the described environment the expenditure would be clearly audible.

In a room where most of us pee-ons reside (mine is 12x26x8), the above expenditure would be indicative of an individual that has more dollars than sense.

Ya can't make a canon sound good going off in a phone booth, anymore than you can make a pop gun sound impressive going off in a corn field.

How good is good enough? When one has optimized their system to their applicable room!

Enjoy the voyage.

In order to enjoy your system after you’ve found out what’s “good enough” you have to establish that as your base line. After that, you can judge the quality of each recording based on its own merits, and not obsess that any problems are caused by defects in your system. It’s very easy to go down the rabbit hole if you listen for defects instead of listening to the music.