Tests verify what the code is doing. And I agree: they are a great source of insight when understanding an unfamiliar codebase. However, comments are typically

Tests verify what the code is doing. And I agree: they are a great source of insight when understanding an unfamiliar codebase. However, comments are typically better at answering the why. If you are diligent about documenting AND updating I don't understand why this is viewed as challenging. Writing a sentence or two here and there is orders of magnitude easier than writing the code itself. And any code review process should help to prevent situations where the code and comments are out of sync. Lastly, I feel like there's a larger human issue. I write comments to explain certain why's in the code because I care about my teammates and I care about the project. If others don't do the same, I think it speaks to a lack of care for their fellow engineers and the work itself. I think, "I just spent five hours figuring out something that you could have explained with a single 30-second comment?" I'm baffled that some engineers think that this is okay.