Not GP but I feel like there's a continual process of the stdlib adding some new functionality to make one such crate redundant (e.g. is-terminal in 1.70), but it isn't done yet.
Yep, that's why I was asking. I'd be very interested to hear of more candidates for uplifting into std.
I guess saying "every project" has 5 dependencies might be somewhat hyperbolic (or at least domain specific) but it would be interesting to know the kinds of things they're talking about that haven't yet been uplifted.