If you look at how toxic that stuff is, it qualifies as a WMD. A KG would be enough to kill 1 million large men with a thousand mcg dose. smaller people would require less to be lethal.
Not a good idea to “inject” Fentanyl the way St. George Floyd did.
(Or in ANY manner).
If China wanted to indiscriminately kill that many, it would crop dust populated areas with drones or dump a few hundred pounds into water supplies. As it is, appears to just be targeting undesirables that they don’t want to deal with—when they take over?