But the price for that is indeed those "redundant stores" which it appears today C++ programmers are convinced explain the slowdown.
I mean sure, the real cause is more likely their incompetent use of the wrong algorithms and data structures or the fact that it's too hard to rely on external dependencies so they're still using a stdlib feature that's known to be significantly slower than the best efforts but eh, it's just a single #include away.
Redundant stores are not some kind of myth. People spent a long time reducing redundant stores in the constructors of the protobuf library, for example, and this has measurable efficiency benefits.
They aren't a myth, but they're very easy to overestimate as a cause of problems.