Originally Posted by
Jeeqbit
I am sure that is their justification for it. But it's incompetent.
They could choose to externalize literally anything else to make up for the extra server processing.
For example, they could have the client directly handle inventory with a different server IP/machine entirely. The only time the server would need to know the inventory is when it's relevant, and in those cases, it can communicate with the inventory server, such as when you discard an item that spawns an S rank.
Another example is they could have the client directly communicate with the chat server that is on a separate IP and machine, potentially allowing for cross-DC FC chat and help support the implementation of a cross-DC Duty Finder.
Ideas like this completely offload the processing from the server and its current IP addresses, or minimize it a lot, but instead they'd rather do that with one of the most security-sensitive features.