IME juniors struggle with making single commits in the first place. What I usually see is a scatter brained approach with more "fix" commits than anything else. This doesn't help with that, does it?
Basically it lets you treat the commits as part of the thing you are reviewing instead of just a minor detail that the UI doesn't care about very much.
The current UIs don't punish you for that as the reviewer mostly sees one final coherent change.