What do you mean by "not playing for many days for them to fix it"? Do you think that in order for them to update backend code that it requires the entire live game to be shutdown for the duration? A simple yes or no will suffice.
1) Speaking plainly? I'd restructure gearing in its entirety. With how mundane it is, there's absolutely no excuse for it to contain that much data that it's prohibitive to further systems design.
I'm not sure what your background is professionally, but as someone who works (not in game design, but financial system design/implementation) with these types of intricacies I can say there are definitely viable solutions. I'd need to know what their development pipeline/processes look like as well as their architectural specifications to make a more educated guess on an actual solution though.
If I took place in the ARR project, one of the MAJOR milestones I wouldn't have let get lost would be identifying/implementing a long-term solution to transitioning the code-base to a more modern platform. I've seen firsthand what happens with a legacy codebase 20 years down the line and it isn't pretty, or cheap, to rectify.
2) Don't be a petulant child. I'm not here "demanding" anything. I'm offering insight into my opinion on decisions made. You're more than welcome to refute any of my posts with your own insight/examples, but spare me the white knight routine please.
3) Just because something is "clearly" working doesn't mean there aren't GLARING flaws or issues on the horizon. If you don't see them that's fine, but it doesn't mean they aren't there. It also doesn't mean something can't be improved either.
Because the way they store data has proven problematic to future systems design. Obviously fixing it isn't easy, but it's a necessary evil. It's going to come to a head eventually. They can't delay it indefinitely.
I'd hate to see a game I love become stale because they're hamstrung by a legacy codebase that all the experienced developers have left behind to work on more exciting new ventures and it's too late/late/costly to fix. I'm vocal about it because I don't think it's too late yet.