Comment by Sebb767

> Unless you have a “every commit must build” rule, why would you review commits independently?

Security. Imagine commit #1 introduces a security vulnerability (backdoor) and the features. Then #2 introduces a non-obvious, harmless bug and closes the vulnerability introduced in #1 [0]. At some point, the bug will surface and rolling back commit #2 will be an easy fix, re-introducing your bug.

Alternatively, one of the earlier commits might, for example, contain credential dumping code. Once that commit is mainlined, CI might either automatically run on it or will be able to be run on it since it's no longer marked as unsafe PR.

[0] Think something like #1 introduces array access and #2 adds a bounds-check in a function a layer above - a reviewer with the whole context will see the bounds check and (possibly) consider it fine, but to someone rolling back a commit the necessity will not be obvious.