Mobiles and floor tiles, and paperdoll art, AND the cc graphics seems distorted. The blaring mishmash of art causes a real incongruity in style (the cc walls clash dramatically with the KR floors) which to me is extremely off putting. I actually like a lot of the monster art, but the avatar and paperdoll art is terrible, and the perspectives used are very inconsistent.
Pleasing graphics are obviously subjective, but the mashing together of two separate sets of art assets with 15 or so years of time between them (which is quite clear in pallet depth and resolution) wasn't even an aesthetic choice, it was a utilitarian one, and in my opinion It simply looks amateurish, and quite off putting.
It's not the CC holding the game back... it's the sub par clients that have been developed to replace it. 3d was hideous. KR was -OK-, like I said I think a lot of the monsters looked awesome, I honestly think if they would have just done another art pass mostly on items, and to take the shine off of almost literally every monster, be more consistent with perspective, replace some bad models (hiryu, dragon, character avatar... looking at you) implement a more nuanced coloring system than paint-bucket, and it probably would have looked fine. EC is just flat out unapologetic mess.
Even you admit that EC is a mess.
I admit I like the CC for nostalgic reasons, but that's not why I play it. I play it because it maintains a cohesive and inviting feel. I would happily play the EC if it looked good, and had a good feel but It doesn't, and with the game as it is, it never will. I am personally all for shutting down the CC if the game could sustain it, because it just works better and is easier to update.
The simple fact remains that form is just as important to many people as function, and to me, as one of those people it's more about a cohesive look than a "modern" one. When look at the screen and see like... up to 4 or 5 desperate art styles (CC, KR, SA, SE, Modern art additions) it just ruins the feel of the world for me. In the CC I can limit that clash at very least in my own personal space by not using any of the newer and less fitting art, in EC I cannot avoid the floor tiles, which are really a terrible backdrop for CC wall sets and item art. I really don't think people requiring a cohesive look to enjoy a game is all that crazy, that's why pretty much all games try to have a purposeful and directed overall aesthetic to give the experience a unique and specific feel. EC doesn't have that, and it's honestly not that much to expect.