Comment by j1elo
A bit more if we consider the "bugfixing" release that was C++14 :)
But yeah it makes sense, given how that was the jumpstart of the whole modernization of the language. I believe it was a big undertake that required the time it took. Still years have passed and footguns keep accumulating... it wouldn't hurt to have a mechanism to optionally drop the old cruft from the language. Otherwise everything stacks on top in the name of backwards compatibility, but at this pace, how will C++36 look like?
a member of the c++ committee (herb sutter) is writing an compiler for an alternative c++ syntax [0], to c++, with the intent to restrict some semantics of the language for less UB, surprises, etc. i think less implementation-defined behavior is incredibly important; rvo vs std::move, dynamic function call optimization, i wish i didn't have to search asm to check for...
[0]: https://github.com/hsutter/cppfront