Well since all 3 of these manufacturers all of a sudden announced their miners it only means one thing.
They have been mining with them like crazy
Bingo
Monero network hashrate distribution (
stats on 8 february)
Roughly 70% of network hashare are on private pools.
Seems to be coinhive, js web miners, compromised pc/cpu instances botnets and Baikal, PinIdea and Bitmain ASICs/FPGAs