Earlier quoted context omitted.
Khesrau Behroz did an amazing podcast about those operations (in German though) [0]. Basically when there was a crack down on providers of illegal sports betting in China, they went abroad and diversified. The betting operation is used to launder the money from those scam operations and betting is still immensely popular in China and done via VPN. Those East Asian sport betting providers are sponsors of many Champion…
There's an interesting "Search Engine" podcast (in English)[0]. Apparently a lot of the people doing the actual scamming are human trafficked and being held in compounds against their will. [0] https://www.searchengine.show/whos-behind-these-scammy-text-...
Wouldn't surprise me, if the DOJ had some "under-the-table" help from Chinese sources, but not in any way that anyone can prove.
If you don't want to sign up for a podcast, John Oliver did a fairly decent bit about it: https://www.youtube.com/watch?v=pLPpl2ISKTg