Tether most of the time slightly valuable than real dolar which strongly indicate nobody printing tether to pump BTC.
It is well debated yet i havent seen any solid argument about fake tethers.
I also think cryptos will eventually crash but stable coins are real deal. They will be around even if people stop trading shitcoins.
They claim to have 46 billion dollars but are very shady about which bank it's supposed to be in. That's quite a large amount of money to hide, it's like claiming I have the Ever Given in my bathtub. Someone would notice.
That would be trivially easy to prove with a simple audit, which they have not done, so the default assumption must be that there is something fishy with them.