Whether or not "10x" exists depend on what "x" is. Some companies have very high hiring standards, so there the "1x" may be high enough that "10x" becomes reall

Whether or not "10x" exists depend on what "x" is. Some companies have very high hiring standards, so there the "1x" may be high enough that "10x" becomes really unlikely. But some companies hire almost anyone who can walk, and then "x"<=0, making 10x pretty achievable. I even expect that some consulting firms to this on purpose, at least if they sell services to customers that are put off by paying according to the value generated by the best developers, they bundle the best developers with teams of low-paid underachievers, where the lead is 10x as productive as those, and where the total output still matches customer expectations. Instead of paying $1000/h for one person they pay $1500/h for a team of 10 people, even if that one person could have more or less done everything on his own.