Progression is important to people and is generally what keeps people around if they’re not altoholics.
For someone pushing 14s and Mythic Raiding, frankly, their progression is not gear. They’re going to have that maxed out immediately because they’re pushing the hardest content well before the people who still need gear get there. They won’t care about gear because it’s a given, not a goal that will help them reach their other goals. Obviously it’s a tool for everyone - but for this crowd, it’s something they already know they’re going to have, because they’ll be spamming the stuff that gets the best stuff from the start.
For people who progress through the game with things like KSM, KSH, or AotC as their goals, gear is a LOT more of a factor. The fact that they’re progressing on these things this far into the game means they are NOT the type of player who blitzes 8s on week 1 in subpar gear and has been 630+ for the last 2 months and 620 since like Week 2.
Gear is part of their progression because they DON’T play like the people pushing 14s who are just going to already have that done and still have goals to chase afterwards. The gear is a clear boon toward the goals they’re still working toward, so they care about it.
I cared about it too. I have KSM and KSH, but still no AotC because I haven’t bothered to go pug it. The Guild is still trying for it so I’ll try to get it with the Guild. And more gear is more helpful to that goal. More DPS makes phases push faster, saves healer mana, skips a popper phase on Queen, etc.
At this point I only need 2 specific pieces from Myth Track in the vault + Spymaster, which is almost definitely either never coming or will be in the Vault. I don’t care too much anymore because the chances of getting one of the few specific items I need is pretty low now and I’m near the max ilvl I’m going to reasonably get. Spymaster is really the only thing that’s going to have a significant impact on my DPS now. Other than like the Queen Ring which isn’t relevant until after we finish that AotC Goal in the first place since that’s where it drops and it isn’t worth it on lower difficulties.
TL;DR People pushing bragging rights keys have the gear by default because of how they play, so of course they’re not going to really consider it as a huge goal in and of itself.
People aiming for lower goals and STILL working on them months into the season still need that gear to improve their chances / efficiency working toward said goals. It is not a given to them, so they care more.