If you have it, it's a self-made dilemma that with careful expert psychological training at great expense and over a long period can be overcome.
I have never had the irresistible concern that my system isn't performing satisfactorily. But I do upgrade from time to time. This is driven mainly by the market. If a component - has to be active not passive - launches and receives very strong reviews then, if it's in my price range - quite high but not unlimited - I go to a dealer and borrow one for two or three weeks. If it makes a big improvement then I probably buy it if I haven't had a purchase for a number of year. Otherwise I don't make changes. Recent changes/additions have been Ortofon Verismo, Audio Reasearch Ref 6, van den Hul The Grail SE. All real game changers, although have three or four other brilliant cartridges - the Grail interprets them all to perfection and for only $20k.
I only get more satisfied with my system, not less so.
I don't sit on edge not enjoying the music because I'm waiting to hearing something I don't like. That is audiofear, a deadly condition that kills the pleasure from music. And from hi-fi.