Maybe, somewhere in the depths of mathematical space, there's some kind of social credit system that is actually good, but that's the same argument as "maybe there is some sort of dictatorship that is benevolent".

Which there might be, I'm not denying that.

The open questions in this case are - "good for what" and "benevolent for whom". Is everybody onboard, is it accommodated to everyone? How many innocent people will have to fall through the cracks, or worse, will end up directly punished by that system when it's in place? How mutable are its rules, who makes them, how will they adapt to change? What's the potential for abuse and bending the system to serve the selfish needs of the powerful few, rather than the needs of the many? A lot of dictatorships started as benevolent, temporary, only as the means to enact much needed radical change. But the historical record so far shows that this dawn is all but destined for the all too familiar sunset.