When we put code into production, even on people’s devices, we aren’t charged by weight. A few unused lines of code don’t slow down our systems nor take up significant memory; indeed, decent compilers will instinctively remove them. But unused code is still a significant burden when trying to understand how the software works. It doesn’t carry any warning signs telling programmers that they can ignore this function as it’s never called any more, so they still have to spend time understanding what it’s doing and why changing it doesn’t seem to alter the output as they expected.
