OK, sure. But now you have a system that has only a monotonically increasing memory footprint. In other words, it's leaking memory. This is undesirable because

OK, sure. But now you have a system that has only a monotonically increasing memory footprint. In other words, it's leaking memory. This is undesirable because memory is finite. This is the core issue behind a lot of the differences between competing programming languages. Languages like C and C++ allow you to manage memory on your own. If you can guarantee through your own program constraints that some piece of memory won't be referenced, then go ahead and free it if you need to. Other programming languages like Java, C#, Python, Javascript, etc. use a managed memory design. A runtime keeps track of memory usage and does "garbage collection" of memory that it can prove is not still in use. The overhead of the runtime and especially of garbage collection is a big sticking point in performance comparisons between such languages and C/C++. Other languages use still other techniques. Rust, for examples, uses a "borrow checker".