I don't think this is enough to completely obsolete comments, but a good chunk of that information can be encoded in a VCS. It encodes all past approaches and also contains the reasoning and why not in annotation. You can also query this per line of your project.
Git history is incredible important, yes, but also limited.
Practically, it only encodes information that made it into `main`, not what an author just mulled over in their head or just had a brief prototype for, or ran an unrelated toy simulation over.