Rust has the advantage of seeing the mistakes of the past and not making them. Many intersting ideas have been tried, only after significant use do we discover which are good and which are bad.
Compromise is sometimes needed. C++ had some ideas they knew at the time were bad, but backward compatibility forced it and backward compatibility is itself a great idea worth the costs.
Rust will have plenty of time to invent whole new categories of mistake, if it ever catches on. It started out with a raft of old familiar mistakes, and shed them over the years leading up to the 1.0 release, such as non-contiguous stacks and green threads. Maybe the way async is specified will turn out to have been one of the mistakes. It has, anyway, mechanisms to shed old mistakes that are not relied on much.
Compromise is sometimes needed. C++ had some ideas they knew at the time were bad, but backward compatibility forced it and backward compatibility is itself a great idea worth the costs.