Depends on the length of the trip and how much you need to carry.

I commuted for years riding 6 miles each way and carrying a messenger bag. I rarely had more than a few pounds, ie. laptop and some junk. I might sometimes carry much more, ie. a watermelon, but for a much shorter distance, typically starting halfway home.

If I had a longer commute, or carried more weight, I'd have scrapped the messenger bag and gone for something carried on the bike. I might also have done so for the commute as it was, except that the messenger bag gave me the flexibility to change bikes more easily.