[oddity]

C and C++ are some of the few languages where the spec goes out of its way to not depend on an allocator, for good reason, and this is well after you've accounted for the majority of the code that, hopefully, doesn't need to do memory allocation at all. The fact that many programmers don't care is an indication that most code in most C or C++ software is not written with performance in mind. And that's (sometimes) fine. LLVM has a good ecosystem reason to use C++, for example, and it's well known in the compiler space that LLVM is not fast. Less recently, for a long time C and C++ were considered high level languages, meaning lots of software was written in it without consideration of performance. But criticizing the default implementation's performance absent a discussion of its priorities when you have all the power to not be bottlenecked in it anyway is just silly.

[dzaima]

The fact that you should avoid allocation when possible has absolutely nothing to do with how fast allocation should be when you need it. And code not written with performance in mind should still be as fast as reasonably possible by default.

I would assume that quite a few people actually trying to write fast code would just assume that malloc, being provided to you by your OS, would be in the best position to know how to be fast. Certainly microsoft has the resources to optimize the two most frequently invoked functions in most C/C++ codebases, at least more than you yourself would.

MSVCRT being stuck with the current extremely slow thing, even if there are truly good reasonable reasons, is still a horrible situation to be in.