As of late there has been a couple of blips around 10x developers.My take is that a lot is missing for many of us.
There is chance that you have worked with a 10x developer but by the context where you were interacting that 10x was negated. It might be a process that is impeding the multiplier, lack of guidance or north star or many other factors.
One that is almost never taken into account is having two or more 10x developers with competing characteristics that essentially negate each other. This I believe is the worst case scenario as it can cause frustration on multiple levels. Also it can potentially be that the 10x individuals are not aware of them being the cause of this situation.
A cycle of constant feedback among team members and across teams is needed in order to pinpoint this case.
The way to solve this negating situation is difficult as it might mean changing way of working in not so subtle ways, a lot of coaching and uncovering of situations that may be hidden in plain sight.
The good part is that once this situation is recognized it might be easier to solve than relying in cover ops to try to move the needle up.