Sorry, that others are equally bad is not an excuse, and also not that Rust's design makes it more difficult to package. Either you care about security or you don't.
My point is that your argument is comparable to faulting Ford for making cars disposable with crumple zones when nobody else has found a better way to meet the crash-safety requirements while satisfying the other requirements too.
TL;DR: It's not a Rust thing. C++ suffers from the same problem when you use templates in your APIs... it just emits a .so file with no contents if you expose only templated APIs. It's fundamentally a problem of "Unless you're willing to spend Swift-level engineering money and still accept compromises Rust and C++ can't afford, dynamic linking in the presence of monomorphic generics is a problem even research languages haven't solved".
...same as the warts in async Rust. What you're seeing is a cutting-edge language slamming up against the limitations of what cutting-edge programming language research has figured out.
At least, with Rust, you've still got the dependency tracking and automatic RUSTSEC advisory tooling you don't get with header-only C libraries.
