Writing clear, concise, and efficient code in C++ has never been simpler or easier. The improvements in C++ over the last 15 years have been qualitative.

So many complex, esoteric, and difficult to maintain incantations that used to be required for efficient code generation are no longer necessary.

I think it has become EASIER: for instance, since C++23 Rust-like move semantics can be used, which provides the compiler with extra information that can be leveraged for the generation of better code.

Or take constexpr - it permits to move computations to compile time that are complex and in older versions either had to be done at runtime, or an ugly workaround had to be used (e.g. assigning a mysterious literal pre-computed in another run or by hand).

How? you can write exactly the same low level code today.