I used to get an itch every three years or so to wholesale change all of my gear. And for many years I was very caught-up in gear, specifically mouthpieces/ligs/reeds and, to a lesser extent, horns. Lately I've been feeling more settled as I've adopted a "reliability and simplicity" standard for all of my gear.
What's the "best" ligature that's easy to use and reliable? - for me, the Rovner Versa. Now I use a Versa on both alto and tenor and sold my FLs, Olegs, etc. One less thing for me to think about.
Same with reeds: what reeds do I like, are easily sourced, and relatively consistent? - for me, Java Greens (although a friend recently gifted me some Rigottis that are very nice). Now I play Java Greens on all of my horns. One less thing to think about.
Mouthpieces are different. On soprano and bari, because I don't play a lot of either, I've stuck with the same (relatively vanilla) mouthpieces for a very long time. They do what I need them to do. I like my sound on both. And I don't play enough of either horn to even care if there's something "better" out there.
Alto and tenor mouthpieces are a little different. Because of GAS, I advocate for every alto and tenor player owning excellent examples of a couple classic mouthpiece designs. For me, on alto it's a great Phil-Tone Custom Meyer (so good I sold my vintage NY Meyer) and a vintage Slant Link. On tenor, it's a refaced Selmer SS Soloist and a vintage HR Slant Link. I favor the Links on both voices. Your preferences may vary (i.e., you may want an excellent Brilhart-inspired piece, etc.). This allows me to occasionally vacillate between the two pieces if I get a case of GAS while knowing that both pieces are excellent. Key for me is knowing that the mouthpiece isn't the problem - it's (almost) always ME.
Horns are similar to mouthpieces. I've owned the same soprano and bari for years and have no desire to change or even try other horns (invites confusion/distraction). I owned the same Mark VI tenor for 15 years, foolishly sold it, and have yet to find a tenor I "click" with in the same way. That said, I'm quite content using my TH&C for bar-honking gigs and my SML Gold Medal I for more intimate affairs. Maybe one day I'll find another VI or a SBA or a BA or a Yanagisawa tenor that has the same connection as my earlier VI, but I'm not actively searching.
I love altos and have rarely played the same alto for more than three years at a time. The two that lasted the longest were a beautiful silver Buescher Aristo Series I (shouldn't've sold it) and a YAS-82ZUWOF# (great horn, but not often missed). There were many, many others in-between (SDAs, Series II, other Bueschers, a "The Martin," a Vito/Beaugnier "Special," and on). Currently I have a few altos in the closet, but for that last few years I most often play my '56 Mark VI alto or my Buescher TH&C (big band gigs). I recently purchased a Vito/Beaugnier Model 37 that lives on a stand in my practice space as a "grab-n-go" practice horn (life with a baby).
The thing to internalize is that you're going to sound 95% like YOU regardless of setup. It's a hard hitting fact but, once you reach a certain attainable level, any differences you perceive across setups, absent MAJOR changes, aren't perceptible to 99.8% of the people who will hear you. For too long I was letting the gear hunt get in the way of my development as a player. Now, I have gear that I trust, that I don't need to think about, and I can focus on ME and what I'm doing with the gear.