Related issue, I carry a man bag (or "satchel") daily in an urban environment. I would not carry this same bag in a backpack setup - too inconvenient for how I use it.

I do see some people walking around with tiny backpacks, I guess the backpack equivalent to my man bag. This would not work for me. I keep my man bag on me while I'm sitting (including while driving), no removal necessary.

I also enjoy wearing my motorcycle helmet throughout the day because you never know. (kidding)