> In my experience, the “small change” merge requests tend to be the most consequential.

I think you're confusing things. The "small change" refers to the diff size. It's far easier to review a one-liner because the impact analysis is limited to that local change.

Of course if your change is something like "mutex.lock()" or "rm -rf *" then these changes will be more consequential than 500 files worth of whitespace changes.