@fix your internet ppl
why do you think SE can not do anything with lag ?
if other games works better going through the same choke points could mean that FFXIV packets are branded as low priority, which is something SE can work on
if wtfast, battleping, pingzapper can work wonders also support the claim there is something with packet structure, as crypted vpn packets are different and run on different ports > thus losing low priority status

another thing they could work on is making their own "squarefast/squareping/whatever" vpn, i mean they already have datacenter, and not all of the player base would use it, should not be a problem for them

i'm sure there are a lot of other ways they can "fix" the lag ...