"#Rust development is going too fast (because they are stabilizing features I don't care about) and going too slow (because they are not stabilizing features I care about!"
There are only so many #RustLang contributors, hours in a day, days in a year to get to everything *now*, and some features are reliant on *other*, less flashy work that needs to happen before they can be even attempted.
But people are putting in a lot of work, the codebase changes so quickly that it is hard to keep up.