It’s propaganda. It is true that deflation would collapse the current system because it is debt based.
Once you get passed the collapse- deflation creates savers, not consumers. An economy based on savers would stop needless consumption of poor products. It would stop the theft of people’s savings and the endless rat race that we are stuck in due to inflation. It would slow down the wealth gap as inflation benefits the wealthiest the most because they have the most access to debt.