The problem with this, as the article argues in detail, is that it leaves a hole in functionality that people need but offers no clear benefit in return.

A movable owning pointer that exposes its pointer-ness in its semantics is a useful tool when you're doing lower-level, sometimes-unsafe stuff with memory layout. The author points out that, because Box does not currently provide this functionality, there are crates in the ecosystem that step in to provide it instead. This middle ground between "raw pointers for everything" and "aliased XOR mutable" is an important thing to support.

This might be acceptable if there were some benefit to Box behaving this way. Perhaps if it actually made a difference for the optimizer? The benchmarks the author did seem to suggest otherwise- many mutations wind up going through a reborrowed `&mut T` anyway. Perhaps the conceptual model of "like a T but on the heap" is enough of a benefit? But being more permissive here doesn't change that model for safe code anyway.

The author dismissed this for much more concrete reasons than "it gets in the way of their point."