How do you know what you're missing?

very good, thought provoking question

i have a few different thoughts it spurs

1) the objective to hifi is not to make it sound like live music necessarily, it is to make it sound realistic, but 'realism' is defined in the eye of the beholder -- so you do need to hear different systems and ideally, have owners describe to you what they feel sounds good about it, and see if you gree (that's why good brick and mortar stores are so important, as well as hifi shows, and local hifi nerd friends and local audio societies etc etc)... i realize these may still be out of reach for many depending on where they live etc etc

2) it is important to try to hear live music in as many form as you can (not amplified), even a street performer singing, playing a saxophone, or a high school performance, or a church choir - remember what the sound of a live voice, a live instrument, sounds like - that purity of tone, how notes rise and decay, no harshness no grain or grit...  is what a good hifi should be reproducing

3) it is easy to fall into 2 traps -

first, that super-clarity and extreme detail is more real and good... that is a 'hifi' creation... real music is not hyperdetailed and disaggregated, it is cohesive and natural; 

second, you should listen enough to define what you like, the sound you like -- don't read reviews or watch you tube videos and let other people define that for you -- for example, some people want their hifi to sound like a rihanna or bonjovi concert... well what you hear at those concerts are huge harsh solid state amps driving huge horn loaded speakers designed to fill a stadium... i would not call that the sound of real music, but you might, and there is nothing wrong with that...

good luck and have fun

I think you are asking a very valid question. After not caring much about music for the past 40 years I’ve jumped into the whole audiophile thing with both feet. I’ve been buying and trying a variety of used equipment. So far I have 3 speakers, 4 amplifiers and 2 preamps with multiple tube options. I’m still struggling with the best way of deciding when one piece of gear is better than another piece of equipment. True A/B testing is somewhere between complicated to impossible and my audio memory only seems to last a few minutes, not long enough to switch cables around. I end up taking notes on certain passages where I think a difference between two pieces of equipment will show up as well as formulating general impressions. All the reviewers that make such definitive and detailed assertions about the speakers and amplifiers they listen to are clearly much more skilled listeners than I am or they simply make that crap  up LOL. I have been surprised at how different the amplifiers sound but I haven’t been able to choose one as being best yet. Most of the tubes in the preamp that I’ve tried over emphasize bass which I don’t like so that is easy. But in terms of what might represent the best, ultimate sound, well I don’t have a clue right now. And then there are funny things where it is hard to determine if a change makes a real difference or if you just want it to have made a difference so you hear your system as being better. I would but my Furman power conditioner into that category. Maybe it made things better or maybe I just wanted it to make things better!

Everything in the following system has been bought based on reading reviews and comments. For like 20 years now. In other words everything you see here. https://systems.audiogon.com/systems/8367#&gid=1&pid=10 Most recently the Moabs were bought exactly the way you seem to be so convinced cannot work.

Clearly either I know something very, very important- or I'm the luckiest audiophile on the planet. Take your pick. Considering where this is posted, all the comments and history, I'll give you three guesses- and the first two don't count.

As for knowing what to do next, it will help to spend some time reading and studying the System info. I wrote it for a reason.

1) There's an old saying: "You never know until you try."
2) Start small and then work your way up, if you're so inclined. In times like this, we need something to keep ourselves occupied and motivated, so why not music and audio.
3) Enjoy the journey; but, also treat the process scientifically and then analyze the results accordingly.

As you start changing equipment or adding tweaks, one of my tricks is to listen to music in the car first, because there's a different kind of focus and enjoyment involved. Then I listen to it again on my audio system with some additional focus on the details or differences that I perceive from whatever new changes that I've made to my system.

End of the day, it's simply what sounds good to you.

Stay off forums, and enjoy your music. Audiophoolery is just another hobby.