"when you expect some photo subjects,"
Not even as flashy as this ^ newer version ^ with the additional racing stripes

This is a Cdn$50 LowePro Adventura.
I pack low key even if I'm invited for the purpose of being an amateur/semi-pro picture taker guy. This size holds my bridge camera in half the width and with about 4" free space above it. On the left half I would put a small palmcorder (e.g. Vixia HF R50), maybe a speed light, often a Tascam DR-40 or Zoom H1 audio recorder, misc. batteries in the front pouch. No additional lenses in the case of a bridge camera.
I will carry that in my hand by the top grip most of the time in the car or indoors. The shoulder strap doesn't even get attached unless I plan to be walking distances outdoors.
This is the basic format of bags I have preferred for decades. This is actually the roomiest one I've ever had and I'm very pleased with it. Discrete, padded and textured, just enough room without having to stuff anything too hard, affordable.
*** Someone passed on to me that a brand name camera technician suggested resting the camera on its hinge end as that is one of the strongest sections of a camera.