so wait, KoG produces efficient™ yet not maintainable code, therefore fixing it is not a solution? Sheesh, I wonder what other features this code possesses. Also nice way of dodging the bullet. "Let's address the underlying issue." – "No, you can't, we must ban them!" If someone suggests to ban all Mexicans and my attitude towards that is "can we please not?", we won't reach any agreement by banning half the Mexicans or peacefully™ banning them.
Also, just to make it clear, I never claimed lag not to be a result of physics or material conditions. However, even after pointing out the arrows of causality, you went on to make the claim, that lag suddenly springs into existence when you get matched against people from LatAm, in the German thread. I think you should ask yourself how those views fit together.
Now, I am going to make an unpopular opinion, a really bold claim. I expect misunderstanding and ridicule and the moderators are going to hate me for doing that. Some may find this trivial, some hard to understand, some correct, some wrong. Here it goes: People from the LatAm community do not cause lag.
Let's say it would be possible to fix the code, how would you make it less lag-sensitive? The issue is the peer-to-peer system elsword uses so what do you want to replace it with? Handing all the calculations over to the server? That would work for us but our lagging friends will have little to laugh about then. Just imagine how this game would feel if you had a delay of ~1s on your characters movement. So that would most likely result in the game becoming unplayable for those groups, wich would be no different from "peacefully banning" them. So again, I'd love to hear your professional input at how you'd actually go about it.
But first, let me explain what is (most likely) the current situation: The network-code has been written at the very beginning of Elsword, so it's been completed for at least 11 years now. Afterwards, a lot of systems where built using this code as a basis. Furthermore, it's highly unlikely that any of the original creators of that code are still working on Elsword, maybe not even at KoG anymore. So not only would you have to change the network-code but also every other function of the game that is relying on it. And you better don't miss one or the game might not work anymore. On top of that, you need to do that without knowing anything about what you're working with beforehand so someone would have to familiarize themselves in-depth with the structure again. No company in the world is dumb enough to expend that many ressources to change something, wich is only performing badly when used in way that was not intended in the first place.
Long story short: A change in the network-code will not happen, no matter how much you wish for it. And even at the off-chance that it did, it still wouldn't fix the problem. The only real way to get rid of distance lag would be to increase the speed of the internet as a whole, all around the world. I'll let you figure out how likely that's gonna happen.
So as long as distance lag is still a thing, the only way to deal with it is to seperate by region thereby preventing people far away from each other of encountering themselves. There is simply no other physically possible and economically sensical solution to this problem. Unless of course, you can provide one with a little more depth to it than just saying "we need to get rid of lag itself easy solved kappa".