I'm going to call BS on 90% of this post, this is how the game was 2004-2007 when I was apart of a LS that dominated their server's endgame.
3-5k EXP was common way back before they boosted base exp on mobs around late 50's-60's. 3-5k was common well before CoP came out, sometimes it was much worse due to how crowded moon, kuftal were, sky sometimes was so crowded you could forget exping there on the weekends.
The endgame was a JOKE.
my LS was the first on the server at killing each CoP wyrm, we knew little to nothing about Vrtra other than it charmed and we one shot it our first time ever pulling it, infact the only things we didn't one shot in the endgame was
-Dynamis Lord due to just unlucky during chain-spell stun one of his tp moves got through and it was something that just happened back then.
-Bahamut rematch, pre-melee burn, we lost our first time and never lost again.
-AV because it was unkillable without cheap gimmicks or it just bugging out. Only kills around this time were Wall of Justice or when it un-expectedly locked itself which later on SE said it was "bugged"
-PW did not exist, my LS had long quit before they added him.
There was nothing challenging about having DD stand under the wing on fafnir/nid, SC+MB aspid, overload BLM+RNG to steamroll KB on all the endgame content pre-toau or limbus since omega/ultima required balanced setups. Eventually you started to stack more SMN's and BLM for CoP wyrms, A SMN army pretty much dominated ToAU HNM with a little melee sprinkled in for Hydra.
I hate to bring up WoW but I was in a top-end guild on WoW during the height of the Ulduar raid before ToC came out, those hardmode fights like firefighter, one keeper yogg, 3 elder freya kills were 100x more harder than anything SE put into FFXI, the end game in FFXI was nothing more but an unbalanced joke, the only challenging thing about FFXI endgame was hoping Ebody,Ridill,D.ring dropped after claiming the mob vs 150 people.