The problem with tech debt is not that it is some poorly designed code in a few repositories that can just be changed. True tech debt is the kind that requires significant architectural changes across many systems and is almost always coupled with major data migrations. You need the rest of the business to agree that you want to invest all that time and energy to fix a problem someone else created 10 years ago. You likely will also need other teams to set aside time on their own road map to address it. You also might need customers to change what they are doing because if software lets you do something, you can guarantee that someone has learned to do it - even if that 'something' was actually a bug.

LLMs don't solve any of those problems by itself.