He started out with among others, std::vector. That has tradeoffs, in that the standard specifies requirements that he may or may not need.
My point stands. The performance trade-offs you're paying for with various C++ features are extremely well understood, and better documented for C++ than most languages.
That doesn't mean there aren't surprises here and there, and obviously there are compiler difference, but the point was that the language is designed so that these tradeoffs are known and documented and for the most part comes as a surprise to people mostly when they don't know the language very well.
It is not a surprise that you can improve on things like std::vector by rolling your own that does exactly what you want; for starters if you know your requirements chances are you can speed up initialization, because you don't need to abide by standard semantics. For starters, if you know you're going to assign a fixed number of elements, you don't need to track size and capacity, and you can often avoid the need for bounds checking.
As for compilation time, that too is very much a matter of paying for what you're using. You can choose to disable debug info, you can choose to not include headers that are bound to result in lots of time spent on parsing templates.
That he's not using many advanced features is irrelevant; his starting point very much had made trade-offs in using functionality that comes with known costs.