The argument against upgrading

This is a great thread with lots of interesting perspectives.  After many years in this hobby I've always believed speakers have the biggest impact on sound quality and to make gains here you need to make big changes.  I have two systems. One is 4X the price of the other.  I could be happy with either one.  I am often amazed how far the less expensive system gets me in musical enjoyment. In the end it's all about having fun and enjoying what you have as coltrane1 suggests.

Last year I embarked on making my system sound better through upgrades. I was looking for a better soundstage and depth. It was easier for me because I knew what I wanted I think most get a bug to make their system better but don’t know what they’re looking for which makes it a rabbit hole.  

First things first.Love of music and musicians should be 90% of your emphasis.Once you have a system that you enjoy your done.Spending your money on music is the prime reason for the hobby after that.Once I realized that my foundational feelings for music were laid down listening to a transistor radio in my bedroom at the age of 8 my pining for better and better gear seemed infantile and juvenile at best.

@newton_john great discussion you've started.  Maybe I'll have a nugget worth sharing.

One thing I haven't heard discussed is the type of music people like.  I think complex orchestral works are maybe the toughest for a system to handle due to all the dynamics and soundstage required to fully reproduce a symphonic piece.  So those that listen mainly to classical, I think probably are more apt to upgrading their systems compared to someone that likes jazz or bubble gum pop music.  The genre does matter.  If your systems goal is to reproduce the nuances of a live orchestra, it's going to be a life long journey.

The other thing I haven't heard discussed is that an upgrade can sometimes reveal flaws in other components.  So what wound up being a single component upgrade becomes a money pit as you realize how you need new cabling etc to refine the sound.  This happened when I demod a T+A Dac200 and realized uh oh, the clarity I'm hearing now reveals that other components need some taming (speaker cables, power cables possibly) and decided no thank you on another rabbit hole.  This is a super important consideration in my opinion.  Sometimes one component change, especially speakers, amp or DAC can throw you down a whole new price tier.

Another thing is that sometimes "better" is not better in all context as maybe some recordings sound more harsh or etched on a better system.  A lesser system can provide some "cushion" to some of the harshness we can hear.  Probably one of the reasons that people choose vinyl or tube amps (not to say there aren't harsh sounding vinyl rigs or tube amps but generally they are "softer") . This isn't to say not to upgrade.  Just remember it may throw you down the rabbit hole of synergy that can mess up your bank account and take you away from listening to the music.

If you really love your system, probably best to keep the speakers and amp you have and try to match components outside of that to tweak it.  Food for thought

Sometimes I have looked back at my upgrades and the incremental improvements made. I don't know that I can say any particular component upgrade "made" the system, but each one did improve sound quality and/or presentation... especially moving up from Audio/Video receivers to a quality integrated amplifier. Then quality separates. Quality speakers are also important and I believe worth the investment, but they are also very personal. I wasted a lot of time trying some recommended speakers that weren't that good in my system. Fortunately I'm done now. Having said all this, my bedroom system is 1/10 the investment yet I enjoy it immensely when I'm in there.