[usefulcat]

> OTOH, 99% of use cases don't care about performance

For many other languages, I'd agree with '99%', but in the case of c++, performance is one of the main reasons it's still used, so I doubt the number is nearly that high.

With hindsight, I'd say that std::unordered_map is fine for what it is, but there are a lot of cases where it's really not suitable due to having a dynamic allocation for each element and the resulting lack of cache locality, and because of that many people have to go looking elsewhere for a usable hash map. There are good reasons why we have both std::vector and std::list.