I really feel this sentiment right here.
Back in the day, through a series of strange and unforeseeable events, I ended up being the first person on my server to get Quel’Serrar. As a Tauren, the thing was just huge! No other weapon at the time was as ridiculous, with the exception of Thunderfury, and later Zin’Rokh. People would send me tells all the time asking where I’d got it from to the point that I had to make a macro for it. Much later, the drop rate was increased dramatically. It didn’t reduce how special it was to me, but it was silly now, seeing nearly every raiding warrior with one.
The same thing happened with Armor sets. Having to raid every single week to get your tier pieces made everything feel more worthwhile when it finally dropped. It took me 4 months of raiding before my T2 pants finally dropped, and I felt freaking epic once my entire set matched. Then, with tokens, it felt like every raid was just a mediocre paycheck you had to save up to get the item you really wanted from the store. Same with PVP every week. Everything looked epic and had particle effects and outrageous features that were extremely unrealistic. There was no in between. There was nothing that made your character feel unique anymore, you were just another glittering mass of particle effects amidst the rest of them.
And then it happened with mounts, talent revamps, changing hunters from mana to energy, transmog, etc.
I haven’t played since Wrath, really. Sure, I leveled through Cata, but you know what, I don’t remember a damn thing about it.
All in all, by the time I quit, it was because playing my character no longer felt like it was MY character. I could race chance, sex change, I could level from 1-max with almost no effort, never needed to actually interact with people or make lasting friends. There was nothing left, no major decisions that determined what my character would be like moving forward.
This all relates to this topic because the mount you rode in Vanilla was just one part of what made your character feel like part of you. Most people only had one because they were so expensive. You could recognize your friends from across town when you saw the right mount/armor. The guys crazy enough to grind faction for a mount that wasn’t their races stood out! It gave WoW the flavor that IMO it seriously lacks right now.