Yes, debt is just journal entries. Is inflation a measure of prices or the amount of money in circulation? “Things are different now”(?), yes, but the near, intermediate, and long-term results of Federal Reserve shenanigans are not a true test of MMT because of the COVID-19 factor. If the new trillions merely flow briefly before hiding in bank reserves, the continued slow velocity there may hide what is really happening for a while longer. Eventually the parabolic increases in M1 and M2 will show up in price levels. How society handles this after “forever low interest rates” will be fun to watch.