To put it another way, the model you're presenting reads well in an economics textbook and I'm sure is exactly how we justify our MMT social policy but it doesn't fully account for actual human behavior. I'll buy necessities (house/food/water/electric/communication) even in a deflationary economy.
When was the last time you went to the grocery store and thought "I better buy this milk today because my money will have less spending power tomorrow"?
They might, however, ask whether they need a car with 30% profit margins or one with closer to 10%.
I don't think the grand social goal is to maximize economic growth. It's a stable healthy society.
Right now it really just feels like people spend on whatever the hell they want to without any thought whatsoever. Consume. Yes good, consuuuume. I'd trade slower economic growth for more responsible spending...