Not for C++ code generated by whole program optimizing compilers. Your "human entered" is doing the heavy lifting. Now that AI is writing code your assertion might be on shaky ground.
C++ can be slow to compile, but as I said, parsing is not the bottleneck. Even for really huge automatically generated C++ files, or old-school concatenated "unity builds", the parsing step is generally tiny compared to everything else.
Coroutines, cooperative threading using fibres, type classes, generics, type deduction, easy interface with C++. The functional style, pattern matching. Flow based programming using 'chips and wires' abstraction.
It has many other interesting capabilities, for example, the ability to change its own grammar, that is rather too much, not for a pleb like me. It has unique (linear and affine) types too. It is really quite a handful.
Go did bring coroutines back into limelight but Felix predates Go by a margin.
Skaller, Felix's author, used Felix as a playground for novel language design ideas, so it was always in a state of flux.
Huh, that does sound like quite the grab bag of features. Think I'll have to find time to further investigate. Thanks for taking the time to elaborate!
A simple recursive-descent parser is easy to write by hand and runs in linear time.