Subjectively I've seen a lot more of this out of China than the US on my socials. Mostly have that impression because: who the hell would go to bat for China on Western/English language social media? Yet I see lots of highly upvoted comments screaming about racism, and interviews of Chinese athletes crying whataboutism, one of them had some cringe story about being rudely splashed by a mean American. None of this nonsense would have a place on my feed if it weren't promoted by botfarms.
Usada doesn't need to use bots to get Americans to pay attention to Americans winning medals. That's what they'd naturally do anyway. Usada also just doesn't have the budget to wage an info war with China, who are obviously quite willing to spend billion(s) of USD on this pissing match we call the Olympics (why, I have no clue).
Agreed that yes, there is plenty of that from the Chinese side too, but I kind of took that as read. The number of US accounts working overtime to deflect and send links around about the Chinese swimmers in response to any social media comments mentioning the WADA-USADA rift has been way more than usual however. I don't know where you're based to know what your social media feed would usually look like from that perspective but I've seen way more pro-US accounts shutting down any discussion of this in the usual "loves America in the way a four year old loves their mom" way than I ordinarily would have done.
China are willing to spend billions on this pissing match for the same reason the US are so keen to spend billions to be top of the medal table: soft power and propaganda. The US is back to doing what it did in the 80s, doing whatever it takes to beat the red menace, it's just that instead of East Europe, this time it's East Asia, and that unlike the Soviets and East Germans, there is not so much direct head to head competition; the Chinese largely collect medals in sports with limited US interest and the US largely collect medals in sport with limited Chinese interest; the arguments are only really kicking off in a couple of sports like swimming where both teams are directly in competition.
Having called out the US for rewriting the medal table to put themselves top earlier in the Games (as mentioned, the US was going to end up on the top anyway, but the US press couldn't bear to even accept being slightly behind when the only sports that had taken place were ones they were less likely to dominate), it would be remiss of me not to then also call out that those same Chinese accounts have been hailing their victory in the medal table by incorporating the medals won by Hong Kong and Chinese Taipei (i.e. Taiwan) into their own totals, counting China as having 44 overall golds (40 for the PRC team, 2 for Hong Kong and 2 for CT). While in some respects I can understand them doing that for Hong Kong, China does not have control over Taiwan to claim that their successes are a win for the PRC, but are hailing it anyway. And of course, they don't then allow a fair comparison by including things like Puerto Rico, US Virgin Islands, American Samoa or Guam to be added to the American total.