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....