I absolutely change bags! I have my larger one when I'm going to the office, or someplace where a larger bag and my wallet are needed. Then I'll use a crossbody to go to the store or a restaurant. I'll pull all the necessities out of my wallet and put it in the crossbody with a lipstick, my phone and my readers.
I like to change the crossbodies that I use (I think I have about 2 dozen) and also the larger bag, but not as often on the larger one.
I have two closets where part are devoted to a closet organizer (that my husband installed). One has all my gorgeous leather bags (all sizes and shapes) and the other my fabric bags. Most of my crossbodies are on a large hook.
The D&B are not heavy for me at all... and I have them in all sizes and shapes.
Enjoy your bags/bag no matter how many or few you own.