Would a backpack or cargo rack be better for commuting?
I avoid backpacks where possible

1) Sweat - I get damp enough wearing just a cycling top.  Putting anything else on top makes it much worse.

2) Crashing - Occasionally I have carried a toolbox in a tramping pack.  One of the worries is "what happens if I end up rolling on this?"

3) Visibility - can be off-set with reflective tape or an overbag/wrapper/cover

You should at least try a rack or basket or frame bag.  See if you can borrow one for a month or so.