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.