I've had one of these since 2010:
Lowepro Terraclime 100 camera bag
https://www.amazon.com/Lowepro-Terraclime-100-Recycled-Grass/dp/B001E5PSFW?th=1
Product Dimensions 5.1 x 10.8 x 7.1 inches
Item Weight 14.4 ounces
Shipping Weight 1.06 pounds
It's a small messenger bag, about $75, that comes with a padded wrap. I've used it constantly for eight years and it barely looks worn. One big space, an inside rear zippered pocket, two front pockets under the overflap and a pair of pen pockets there too. No velcro ... slide and latch closures.
I've stuck all manner of gear, compartment padding, etc in and out of it over the years. It's small enough to carry all the time and big enough to do serious carry when needed. It's light, and lightly padded. Your gear inside, with a couple of wraps, conforms to your body when you wear it.
The Terraclime 100 is discontinued but new old stock continues to be available.. A very comfortable, simple, easy to live with bag. I often drop the M-D and two lenses into it, and if I need it, I can stuff the iPad Pro 9.7 in there too, with plenty of space for batteries, cards, file transfer dongle, etc.