Getting a given task done fast does not make you a 10x developer.
It's 10x over time, not 10x for a given task.
There's the fast way of doing something, copy and paste some similar code, tweak it with your goals in mind and you're golden.
You also copied every single bug in the code you replicated, and further polluted the base of the software, which is already a steaming heap of unmaintainable garbage because the impetus is for speed over quality, and tacitly encourages developers to do what you just did.
Or you could refactor. You look at what needs to be done and how the current API limits your ability to implement it.
Update the API to integrate the required features, and refactor if the gradual build up of changes has rendered it unwieldy.
Quickly and cleanly implement the new requirements against the improved API.
You just spent a day and a half implementing something that could've been done in two to four hours, ignoring whatever manager was wondering why it was taking you so long - but the next time you need to make a similar change you'll be done with dev in half an hour.
And when that happens the code you write will be clean, simple and unlikely to introduce new bugs.