If garbage collection helps, you no longer have ownership, because a single place where a value is dropped obviates the need for GC. If you no longer have owner

If garbage collection helps, you no longer have ownership, because a single place where a value is dropped obviates the need for GC. If you no longer have ownership, you no longer have use-site mutability, because no single place controls the mutability anymore. If you no longer have use-site mutability, you no longer have the good type system. The borrow checker is what makes it work.