I dunno, C++ has a similar level of complexity (lots and lots of features and fiddly libraries). Blindly writing C++ causes segfaults and undefined behaviour too.
The difference is that Rust complains at compile time, deterministically. So Rust _feels_ like it's tripping you up, whereas you would have been tripped up (without realizing it, often, because runtime) in C++ too.
The second difference is that people are used to C++ and don't recall how complex it is.
A long time of the whole world of software changing too.
If Rust wants to be useful it needs to have a lot of features devs expect from languages of that kind; plus all the features needed for memory safety; hence the complexity.
All these different mutable/shared/etc. combinations look inherent to the problem, i.e. inherent complexity. You'd have the same problem in another language with the same intended goals. So what is the accidental complexity that Rust is adding to the problem?
Unfortunately it is just the inherent complexity that is troublesome -- there is a steep learning curve to get up to speed with Rust and I am worried that the barrier is too high for most people to climb up -- either that or it will take a while and a whole lot of tutorials/cookbooks until people get familiar piecemeal with all the ways to work with Rust....
I remember Ada was considered complex back in the day and now with all UB and specific compiler extensions, C++ has become much more complex with Ada 2012 and SPARK getting industry adoption in high integrity computing space.
The difference is that Rust complains at compile time, deterministically. So Rust _feels_ like it's tripping you up, whereas you would have been tripped up (without realizing it, often, because runtime) in C++ too.
The second difference is that people are used to C++ and don't recall how complex it is.