I own several LC bags around this size (9 1/2 x 7 x 3 1/4 inches).They can hold all my essentials for many situations, are light and easy to carry, and look chic. Rather than thinking in terms of your "regular" load of stuff, you might be surprised with how little you actually need to carry at certain times.
All I really need are my keys, phone, and wallet. The rest is for the what ifs! I have a friend who told me how free she felt carrying no bag at all. She had all 3 things in her big winter coat. [emoji1]