You still have to deal with the fact that existing APIs use a broader range of types; using Rc everywhere in your own code doesn't save you from dealing with library interfaces.
Also "stuff like" is kind of the problem; all of the smart pointer types have differences that matter, and none of them is general enough to cover all use cases. Arc<Mutex<Box<T>>> comes the closest to a "general" solution, but the boilerplate is rather a lot just for the sake of not having to think about this stuff, and you still can't use it if T isn't Send.
You're really picking a fight with the language if you insist on avoiding making these decisions, and in the end it will just slow you down even more than going with the grain. And to add insult to injury, if you write all your code like that it'll likely be slower than OCaml or Haskell anyway. Rust can't keep up with a good GC on allocation throughput; the performance advantages come from managing things yourself (and avoiding heavy allocation in the first place).
Rc and friends are useful, but they don't make the problem go away.
As I said, it's not that it's even really all that hard. But it is time consuming.