Those accusations are almost solely words of one man who fled the US in 2015, and has had an address there since 2011. A man who contemplated suicide and then blamed his wife. He didn’t get paid enough so he attacked the integrity of many athletes that contested their suspensions and won them in CAS. The last time I saw his face in the news he looked like a completely different person, like a slightly younger version of Scottish actor Brian Cox (of Manhunter, Braveheart, Rob Roy, Bourne Identity, etc fame). Before that he had a full face mask on with sunglasses.
I know in the Western world the flavor of almost every month is to target Russia, and this campaign spilled over into sports in 2014. Instead of trying to build individual cases, they went for the ‘state sponsored doping’ cause it was convenient and the media ran with it and that was also very convenient, went hand in hand with their theory that “Russia stole the elections…” (which has been debunked as well).