It's self-reinforcing. If commit history is reasonably clean, the barrier to doing code archeology is lower, so you reach for it more often. And if you do code archeology often, you develop a better sense of what's a clean commit history and what makes commit messages useful.

The need for code archeology depends on a project. When you writing a lot of new code it's probably less important than in a legacy thing where most changes are convoluted tweaks made for non-obvious reasons.