I do prefer the "with"/"try-with-resources" approach because it is explicit.

With RAII in C++ there's no visual difference between dumb data objects and objects like locks that are created and held on to mainly to cause implicit side effects.

In Rust this also prevents the compiler from dropping objects early - everything must be held until the end of its scope for the 0.1% of cases where you're RAII managing some externally visible resource. In those cases I would like the programmer to denote "The exact lifetime of this object is important", so the reader knows where to pay attention.