I use a Spider Holster with the DSLR, in order to move the weight from my neck and back to my hip; it’s also a way to satisfy my inner kindergarten child, prancing around as a cowboy. 
They also have equipment for mirrorless cameras, e.g. mounting them on the straps of a backpack:
I will be getting a PGYTech Beetle for similar reasons, and maybe their strap (I find it delightful that they have ONE strap, so I don’t have to choose 
), but this does not affect how I think about bags.
Specifically, when I am taking photos, the camera is on my person, and when I am not, a neoprene case inside a plastic bag inside whatever bag I am travelling will do.
I am not questioning that bags are useful for some people, especially large camera bodies with larger lenses and a ton of accessories, including a tripod. I just find that the less gear I carry the more I enjoy photography.