When you're just learning it Rust can definitely be a lot less productive and a lot more frustrating. But once you get to an expert level I think there's just no contest, and you can churn out code high quality code significantly faster than you can in C++. (At least that's how it is for me, and I've been programming C++ for over 10 years and I'm don't intend to ever go back.)
Indeed. IME (around 10y C++, mostly c++14 and c++17, and 6y Rust), I measure x2-x3 velocity in Rust, a lot of which comes from the tooling, a part of which from ub-freedom and much easier and safer parallelism, and the rest from the expressive type system and functional polish.
This is for initial development. Factoring in the maintenance over the years I suspect it tends to an order of magnitude of difference.
It also depends on one's familiarity with the languages, I've used both pretty extensively and can't comment on the velocity when just learning.
Just my experience, YMMV.