My statement was referring specifically to an "individual contributor" and I said as much in the original post. If you are a team lead, by definition you aren't just an "individual contributor" and you're also not the "10x developer". Your increased effectiveness is because you have a team under you and you are a "force multiplier".
but "careful, paranoid engineering" does too. Almost by definition, your really junior employees don't really know how to do the latter. (They'll often be able to cargo cult it, which can be a start, but they won't really understand it.)
I also specifically said the difference between someone with 10 years of experience and someone with 20 years experience. If you have 10 years of experience -- you hopefully aren't a "really junior employee".