People always tout this as a huge reason for not wanting a too big std in Rust (or "too useful" either), but IMHO that's just talking about reaching theoretical optimals, while leaving the community for years without good guidance via providing a opinionated practical and pragmatic way of doing things. Which I find to be a very unhelpful stance for a tool such as a programming language.

If a design of some std package didn't pass the test of time, and a new iteration would be beneficial, the language can leave its original API version right there, and evolve with a v2, with an improved and better thought out API after learning from the mistakes of v1.

Prime example: "hey we found that math/rand had some flaws, so here is math/rand/v2". A practical solution, and zero dramas as a result of having rand be part of std.