For me, it's getting a little more boring than ever before. I'm not saying that because it's getting old, or because I'm grinding the same stuff, that was always the case and I didn't mind it then either. It's this stupid AD thing making me unable to play other characters.
I used to able to gear a character out to be ~80% as strong as my main in just a few weeks of light farming. +10/11 used to be more than enough to place first in damage against all but the best geared and most skilled players.
I recently geared a full dully +10 char, fully enchanted on every slot, +10 weapon, and it's still about half as weak as my main with a +15, if even. My main is still in full 90 gear and it's more than twice as strong because of that one weapon. I have dreadful luck, I know I'm never getting past +12 again, so at best it'll be 60-70% as strong as my main, and in that case what's the point?
In the same fight, with about the same skill level playing each char, I can finish in 5 minutes on my main with a +15 and over 15 minutes on my new character with a +10.
The only gear that really matters now is the weapon enhancement, and maybe your defense level. There's nothing to aspire for, nothing important to farm. Enchants aren't all that rare, and at best they're a 1% dps change, aside from the cheapest ones (Chaotic, temporal, stigma, valor). Balance is mathematically pretty close to useless with high AD. Crit is fairly easy to cap. Releasing the damage cap is incredibly expensive for a trivial gain. No matter what I put on my alt, only one thing will bring it close to my main, enhancing that weapon.
It's boring playing one character. It's boring pouring all my money into the RNG adventure instead of gradually raising power through scrolls and stuff. It's boring to play well at +10-12 and get absolutely destroyed by +13 and up, to the point where you wonder why you even joined the boat.
There is plenty of challenge at endgame I think we can all agree.
Due to the very distributed population and not a lot of new players, the "challenging" low level content like polar bear was becoming frustrating instead of fun for new players. It really was hard to clear in level-appropriate gear with no help, boats took an eternity to fill up, and the rewards for finishing those fights other than quest progression were worthless. You basically had to wait for or ask for a carry.
I agree they should have mildly challenging optional content but on balance it's probably better to ease people in.