There is a lot to unpack there.
- My comment is not about if they are real or not, tbh I don't give a fuck this will not be the reason why I think the CCP sucks ass.
- Who the fuck is talking about the US? Did you not read the part where I said every country with the death penalty sucks? This is just plain whataboutism.
- There are many problems with the death penalty (in any shape or form) and in my opinion it is very likely a mobile execution center would exacerbate the problems. More technical mistakes, more false executions and of course more potential for abuse, especially from a party that does not have a great human rights track record.
- Why bother? For example because it would be stealthier than an execution squad. Or for the same reasons the Nazis invented the Gas chamber: Because it's more humane. Of course not towards the victims but towards the people doing the killing. It's easier to cope this way.
I might actually agree with your last point, it does not really make sense. But on the other hand, does it need to make sense to be true? I don't think so.
But also like I said before: I don't care and neither answer will change my mind about the CCP.
I answered this in a different comment.
edit: because I suck at editing