If upgrades were no longer possible would you be

Yes I am happy now and have been for over 2 years with no upgrades. I was not happy for almost 6 years however.
BTW your system is not average to you. It must be excellent to you since you are happy and content. It must not doesn't compare poorly with other systems as you hear it. Those better systems are not better enough to inspire any desire for them.

I'm in a scary-satisfied state with my hifi. My wife tells people I'm acting weird with my hobby. My attention is drawn by the performance and creativity more than the sound. I think that's one of the basic goals of this whole thing.

If it were to never get better that would be fine with me just so long as it never gets worse.
There is always room for improvement but need for improvement is another matter.