Some years ago I was working for company X on product Y. All in all it was quite a nice experience. We had a small team working on a code base that was pretty good. It had nice tests, not too many bugs, and when issues did arise they were usually easy to fix. Eventually the project was deemed good enough and we were transferred to work on different projects.
I have no idea what our "industry standard performance multiplier" was when we worked on that project, but for the sake of argument let's call it 1×.
The project I got transferred to was the thing of nightmares. It was a C++ project and all the bad things that have ever been said about C++ were true about that code base. There was not much code but it was utterly incomprehensible. There were massively deep inheritance hierarchies, , compilation speed was measured in minutes for even the most trivial changes, and so on. It was managed by an architecture astronaut that, as one is wont to do, rewrote existing mature libraries as header only template libraries that were buggy and untested (one could even say untestable).
Thus overnight I went from being a 1× down to being a 0.1× or possibly even a 0.01× developer. Simply trying to understand what a specific function was supposed to do took hours. There was, naturally, a big product launch coming up so we needed to get things finished quickly. All in all it was a stressful, frustrating and unpleasant situation to be in. And that was not the worst of it.
After a few weeks my manager wanted to talk to me in private. He was very concerned about the fact that I had not achieved any visible progress for a while. Then I explained to him in detail all the problems in the current project. I even demonstrated how compiling a simple helloworld-level program with the frameworks we had to use took tens of seconds on the beefiest i7 desktop machine I had available. He did not seem to be able to grasp any of that as his only response was "but you used to be so productive in your previous project". Shortly thereafter the same boss started giving me not-al-all-thinly-veiled accusations that I was just slacking off and that this could lead to serious reprimands.
This story does not have a happy ending. The project eventually failed (due to completely different reasons, though), money was squandered and almost everyone involved got fired. In the aftermath I seriously considered getting out of the software engineering business altogether. The entire experience had been so miserable that becoming a 0× developer was seriously tempting.
Is there something we can learn from this?
The "×ness" of any developer does not exist in a vacuum but depends on many organizational things. The most obvious one is tooling. If you have a CI where tests take 30 minutes to run or your developers have underpowered old laptops, everyone's performance goes down. In fact, the overall health of the code base probably has a bigger effect on developer productivity than all developers' skills combined.
But even more important than technical issues are things that promote healthy team dynamics. These include things like blameless postmortems, openness to ideas from everyone, permission to try new things even if they may fail, stern weeding out of jerk behaviour and, ultimately, trust.
If you work on getting all of these things in your working environment then you may find that you find yourself with a 10× team. And if you do, the entire concept of a single 10× developer becomes meaningless.