Different bags for different purposes. Daily use, and occasional use.

I have daily commute bag for my work stuff, laptop, clothes etc. (Arkel Commuter) indestructible and 100% reliable for daily use. Not really for getting groceries though

I have 2 Banjo Brothers grocery panniers that I use for additional cargo space as needed. Somedays I bring one with me on my commute if I need to make a stop or run errands. Or I use them both to go the the grocery store, beer store, picnic or whatever. These are great for utility carrying of stuff, but not nearly robust enough for the daily commute. In my mind they are occasional use bags. They are inexpensive and super useful to have in the stable.