[khitchdee]

C++ adds a layer of functional indirection above the level of the C structure. This is what causes the bloat. The implementation of the C++ object vs. the C struct. Iostream is implemented as an object. C++ is definitely more convenient and that was the intent of its creators. It does not replace C but provides a more convenient alternative to using C structs and fn pointers at the cost of a small performance penalty (maybe slow and bloated is over-expressing the penalty).

[qsdf38100]

This "bloat" of C objects you mention is only there if you use virtual functions. Same as using function pointers in a C struct. But in some cases C++ can avoid the dynamic indirection thanks to templates like in std::sort while C's qsort gets passed a function pointer, called for each comparison.

Iostream do use virtual functions but it’s not the reason of its suboptimal performance. The main reason is that some strings will be copied, allocated and freed during the construction of the whole expression while printf can do its processing with minimal dynamic allocations.

[khitchdee]

No virtual fns means no inheritance. Also, you can blame the implementation and not the language. But real-world it is slower. Can't say by how much. Why bother?