Draft FAQ: Why does the C++ standard ship every three years? (2019) (herbsutter.com)

Because they want to make sure that the effort to make C++ ever more complex, baroque, and a pile of shifting sand continues unabated. I'm being sarcastic, of course, but it has felt like that's been their goal for many years now.

Because this time, they are doing it right. /s

Compilers have anyway too few flags.