It’s been pretty clear for a while that Nikita has been looking at the ways twitter is bad- foreign accounts stoking hatred in the west for cash.
He started putting in ways to change it and put in better incentives (not monetizing this rage baiters, disclosing country of origin). The problem is, the people he screws by doing that are the exact accounts Elon Musk loves, do every time he wanted to make a change cat turd would go screaming to daddy. Hence why I find it so unsurprising he’s quitting.