My first car was a hand-me-down van from my dad. It was big and akward, but I mostly used it for regular car things, and it was kinda bad and difficult at those, but I could manage.
The fact that it did the things I wanted it to (barely), while allowing me to ignore 90% of the design intent behind it shows it was designed in an opinionated way, just not in the way I cared.
Same goes for C++.
> A lot of the C++ community doesn't use these features
That they even have the possibility shows how un-opinionated C++ is.