All the anti-China subs has grown multitudes more users than Sino since last year, easily enough to drown out pro-Chinese voices. Statistically, we should see more anti-Chinese bots and manipulation occurring.

Also all available research doesn't suggest CPC has foreign manipulation toolset on western social media, except last years twitter "disclosure" about state level manipulation on HK without any explanation and attribution. Turned out to be ~200 twitter accounts, which... ok could be from Chinese state or bored PRC nationalist script kiddies.

Also 50c doesn't operate abroad, they don't engage in argumentation, only lazy platitudes about positive Chinese news items - they don't draw attention to negative news. All the shill accusations doesn't account for this fact that 50c glorifies instead of defends China. The latter pattern requires too much effort. Official 50c are mostly state employees trying to meet msg quotas on domestic social media. Also China would not waste English proficiency trolling on reddit, English speakers with proficiency to trick western audiences are making bank working in industry and not the state. Chinese foreign propaganda MO is pouring a few hundred billion buying ad space in foreign news papers. And lately they've been growing twitter and other microblogging platform accounts for their diplomats to troll US. See US bioengineered weapon.

E: Just to add the parsimonious explanation about the amount of pro-Chinese perspectives is that the vast amount of Chinese diaspora is engaging online discussions since they are witnessing the effects of western propaganda targetting their country. There is a ridiculous amount of biased reporting out there. Increased sinophobia etc, it's in their interests to clear the air which occasionally leads to doubling down on nationalist rhetoric.