It's a combination of software and scalability issues. There's no ONE thing the lemmy developers can code that will magically fix it, and there's not ONE thing the admins can do to make the current code run on the currently deployed infrastructure. The software was not tested to work at the volume and scale we're seeing between the top 5 instances, and not all of the admins are prepared to work through it. It requires a lot of "togetherness" to change and test the code with "right-sized" resource and operations management. Pretty mature stuff for a rag-tag group of reddit refugees. :)

Right now, lemmy.world's admin team is probably doing the best job of collaboration and communication (props to everyone else too.) Prioritizing the issues and focusing on them for the sale of the actual users is the key. Some admins are just expecting the next upgrade to fix everything without being involved. Blaming the software is not the solution. Eventually that might be a good position, but this early in the game it just won't work. Everyone is still working hard!

Lemmy was written an tested at what is essentially: "raspberry-pi scale" and has been forced to make the maturity jump to "could-scale," practically overnight. It sucks the growth isn't smooth, but it is totally understandable.

tl;dr There is no github issue because there isn't one problem in code that can fix it.