I have an idea for a product that would monitor your code as it runs in production with the intent of identifying code that is no longer called. The tool would then open PRs on your codebase to:
1. add tracers to give confidence the code is truly unused, and; 2. remove the code no longer being used.
Obviously, security and performance would be paramount.
Is unused code something that your team is concerned about? Would this be something people would be willing to pay for on an ongoing basis?