I think the real way you can reduce technical debt is by valuing code less, not comments more.
Comments are vital, but I prefer everything be refactored to make the code the comments, which only happens if you get naming right, the language, libraries and the frameworks don't fight you. Which is a lot of ifs. Even then you need the comments to label parts of code that are exceptions to normal practice, or to fix particularly subtle bugs so that you prevent regressions from happening. (If you want tests to do that, it doesn't obviate the need for comments - you probably want the comments in the code and the test, because you don't want it to be standard practice when you are editing code to discover a new all the failing test cases when you make a change)
Comments are vital, but I prefer everything be refactored to make the code the comments, which only happens if you get naming right, the language, libraries and the frameworks don't fight you. Which is a lot of ifs. Even then you need the comments to label parts of code that are exceptions to normal practice, or to fix particularly subtle bugs so that you prevent regressions from happening. (If you want tests to do that, it doesn't obviate the need for comments - you probably want the comments in the code and the test, because you don't want it to be standard practice when you are editing code to discover a new all the failing test cases when you make a change)