I’ve been working in the industry for two decades, and I think commit messages is not the best place for storing decisions and associated context. I personally prefer ADRs.

Two decades and you don't see any value in writing down what's currently in your head?

Anyhow, ADRs are good, but they stand for Architectural decisions, not every decision is at that level.

In general, if there's a better place to store explanations, do use it, but often, in many projects, commit messages are the least bad place; and it's enormously better to write there than nowhere at all.