Since March I've rarely used a handbag. I have pockets in at least one item of clothing I'm wearing, and all I usually carry with me is my mobile phone with a bank card and face covering exemption card in the case, a tissue, and my car or door key. Lately I have taken to carrying a small bottle of hand sanitiser. If it rains I wear a coat or jacket with a hood - and yet more pockets!! I have a wonderful sense of freedom without all the clutter that comes with carrying a bag!!
Of course, I do use shopping bags. I have a wonderful collection of hessian ones, and have lost count of how many, though perhaps not as many as your sister-in-law's bags, biba
I think it's time a charity shop received all those hand/shoulder bags I'll never use again!