It's also questionable how much of that will be passed on at least for Americans. My dad and step-mother are in their mid to late 60s and have ~1 million net wo

It's also questionable how much of that will be passed on at least for Americans. My dad and step-mother are in their mid to late 60s and have ~1 million net worth but a lot of that is wrapped up in their house and retirement accounts, which will probably be taken by the state when they require care in their old age. Nursing home care will eat through all of that without blinking. There's a huge difference between 'retired with a 500k paid off house and about 1 million in net worth' and a 900 million net worth even though both are 'millionaires'.