If I remember correctly my econ classes, the multiplier exists because of fractional reserves in banks. Your $100 on deposit creates $90 in loans, those are deposited to create $81 in loans, etc etc. So $100 of initial deposit becomes $1000 (x10) moving through the economy. 100 USDT locked $100 on deposits, and those can only be lended to the US government. So the multiplier is x1.