Ok, but how can you as a fed say that if you double the money supply the velocity will stay the same forever? This is the ridiculous issue with this MMT theory

Ok, but how can you as a fed say that if you double the money supply the velocity will stay the same forever? This is the ridiculous issue with this MMT theory. How the hell can you be so stupid to assume that just because money velocity is slow now, and you pump lots of money into the system (actually you give it to financial companies, another red flag), it won’t cause inflation in a few years when things pick up? Especially after a pandemic?