IMO these are the major downsides of Rust in descending order of importance:

- Project leadership being at the whims of the moderators

- Language complexity

- Openly embracing 3rd party libraries and ecosystems for pretty much anything

- Having to rely on esoteric design choices to wrestle the compiler into using specific optimizations

- The community embracing absurd design complexity like implementing features via extension traits in code sections separated from both where the feature is going to be used and where either the structs and traits are implemented

- A community of zealots

I think the upsides easily outcompete the downsides, but I'd really wish it'd resolve some of these issues...

At least apparent complexity. See "Expert C Programming: Deep C Secrets" which creeps up on you shockingly fast because C pretends to be simple by leaving things to be undefined but in the real life things need some kind of behavior.

You can ignore most of the complexity that's not inherent to the program you're trying to write.

The difference is C also lets you ignore the inherent complexity, and that's where bugs and vulnerabilities come from.

I'll take good complexity over bad simplicity any day.

Rust makes explicit what the C standard says you can't ignore but it's up to you and not the compiler. Rust is a simpler and easier language than C in this sense.