You're spot on because inflation is what allows the whole thing to work. If instead there was rapid deflation on the trillions of debt held by Americans it would cause many to default.

But hell, talking about inflation is so weird because to most I feel like it just means the things people buy are now more expensive. Things are more expensive because people are able/willing to pay more, they're just in the losing side of the disparity. It wasn't inflation of the dollar that caused housing prices in places like Phoenix to climb over the past 20 years, it was people with more money than them moving in from places like California.