To me people pushing for self checkout sounds like somebody preferring self service over full service gas stations - I find it difficult to understand.

For gas stations, it’s faster for me to not have to wait for an attendant. I don’t have to let someone else touch my credit card and/or give them my zip code. And I don’t have someone else continue filling the tank after the pump automatically stops, preventing gas to drip down the side of the car.

For retail stores, self checkout is quicker, as stores are mostly not staffed well enough to compete with the self checkout lanes.