>>58667619Gen 9's problem was a combination of poorly optimized open world slop adding an extreme burden to the Switch's specs, unaddressed and untested memory leaks (since no one playtesting left the game running for longer than a few hours at a time), and especially unaddressed Union Circle bugs since they probably didn't have a way to set up a local instance to allow them to test online interactions without getting their devices banned automatically by the "hey, you're not supposed to be on here yet" checks from Nintendo.
How do I come to the conclusion on "no online testing"? Simple, because if they knew this would happen, they would've done something to address it, this was literally one of the biggest selling points of the game aside from "IT'S OPEN WORLD!!!"