On the other hand, people like Scott Meyers have spent their lifetime and careers explaining its intricacies, without solving any real problems.
It can be misleading to think of standard header code (especially template code) as "idiomatic C++". It'd be better described as "idiomatic standard-library-implementor C++", since the folks implementing stuff in std are operating under a whole set of constraints that don't affect ordinary C++ programmers. Arbitrary user-defined symbols that could be in scope, user-provided types that could have overloaded operator-comma, etc.
Designers and implementors are traditionally under a very different set of constraints than "average users" (who in this case are programmers), though their goals do align. But this leads to very different set of assumptions, optimizations, and tools being available. Things that would generally be overkill are suddenly very viable and worthwhile goals to achieve (e.g. micro-optimizations add up repeatedly so they're very worth it, vendoring is much more useful to control dependencies/scope of bugs), and vice versa.
So I wouldn't be extremely miffed if you look at libstdc++ or libcxx or <whatever> and find it somewhat unkempt or gross compared to average code. It's often very much not-average. In fact it's likely given careful understanding of the constraints that code exists under -- you'd come up with similar results.
And what's with the Scott Meyers ding? I think of him mostly as an educator and in that respect he's very accomplished.
Each time I hear a discussion between programmers, it is always these arguments of whether build tool A is better than build tool B, or whether VCS A suits their workflow better than VCS B, or how cool is the latest language feature. I never see programmers discussing the merits of their solutions, regardless of the language or environment.
What we don't have in common are the exact problems we are trying to solve. That's where design patterns and other higher level concepts become useful. Because the problems and solutions are so context specific, they happen on mailing lists. Tool discussions, on the other hand, are more generic and I think that's why you see them in more places.
Sometimes people think they know their favorite language, but most would fail a language puzzle quiz.
Right, I'm sure Go is the one and only language out there without a single pitfall or quirk.
But that is especially true for C++. People who are confident in knowing it often lack the fundamental C knowledge (i.e. pointer arithmetic, the complete C type system, the subtle conversion and promotion rules, etc.), but would insist on knowing C++ very well just because they know how to define classes, virtual functions and throw a shared_ptr or a vector or a map at every problem.
Nor can they correctly point out all the cases of expected semantics, UB and implementation specific behaviour.
Regarding the fundamental C knowledge, part of it just leads to bad C++ code.
In C++, you fight with the language first and then face the problem.