Sure, if that works for you, it's easy. Stuff like crossbeam::scope only solves a subset of the problem, though. When that solution doesn't work for you, it's a pain.

Using a scope is, strictly speaking, less powerful and more annoying to work with than a more general system of linear types. It's like Go's defer, or C#'s using/IDisposable... they work in certain scenarios, but there's a percentage of the time where a lexical scope or function scope doesn't match the lifetime of your object, or can't match the lifetime of your object.