Can one ever be "done" in this hobby?

For me - the sound is just part of it. The music is another part. I’d take my favorite music on a lessor playback than best playback of a track I don’t enjoy. But the tweaking, the look, the stuff is likely the biggest part. I tweak about everything I have. Sometimes, I make it worse, but it is always fun to tweak. That said, we are remodeling a house right now and  I can justify thinks for work, but for listening, that is not so easy.  My computer streams and drives a Qutest DAC, using the fancy cables, Goal Zero 1000 battery powered (sometimes) Cary CAD-300SEI SET amp with way more power than I need, and some Watkins gen 4 speakers, REL sub, and Sony MDR-Z1R headset, with RODE mic.    Its for work, as I said.  When I leave work, I don't listen to it (but I get 8+ hours a day).
I think about other speakers I might try, but have a hard time believing any bookshelf/desktop will be better for near the $ of the Watkins.  So I'm done - for work. 
When the remodel is done I think I'll find some budget higher power tube stuff.  If the wife enjoys it, it could become very expensive. 

For me, the hobby has three aspects; the music, the gear and the technology.  As a result, at any given point in time, any of the three may beckon.  I usually ask myself, how much am I willing to lose when its time to move on and try something different.  This allows me to make "no regret" type decisions and enjoy where I am in the moment...knowing that its OK to move on when it feels right to do so.

You'd think with all the improvements we hear about from one year to the next that the best audio system for a given price today would wipe the floor with the best audio system at the same inflation-adjusted price point from ten years ago.
I'm not so sure that's true. In fact, I think we'd find the difference subtle.  Which is a reason to pause.
I only came back to this because my old system broke down.  I did not find speakers at the equivalent price point that blew away my old Thiels. In fact I found quite a few that didn't hold a candle to them.  As for amps - well the differences are subtle there even among current models.  DACs have improved, I think.

Concentrate on the fine points of the MUSIC, not the SOUND and you’ll be happy.

Sorry, tried that. Didn’t work. 😢 For me SOUND=MUSIC