Surprised to hear vivo and xiaomi beating samsung... Great for the consumer.. Was thinking of buying s23 ultra may go for one of them after testing at a physical store
You need to understand few points.
1. Samsung phones have the same processed look(sharpened bright looks) and same with iphones(warm tones)
2. Whatever the condition of environment these phones will drag the look to fit into their style of imaging algorithm.
Xiaomi has a very distinct less processed look with the 75mm rendering fabulously
The microcontrast is little less.
Processing even with HDR is not extreme unlike its previous models.
Vivo I noticed in portrait mode does brighten the face with processing after capture
The result is not bad but it would have also been great if left as it is.
Vivo has portrait mode with 2x zoom
Xiaomi mostly with 3.2x so indoors you struggle with Xiaomi(have to back out a lot)
Plus indoors Xiaomi doesn't make a fast shutter speed(1/25s) in most conditions hence blurry images are common