In a hundred and twenty or thirty years or something, the dollar will have inflated by 1000 times, so a billion dollars then will be equal to a million dollars now. It'll cost a billion dollars for a nice four bedroom house.
But we'll have had a hundred more years to produce anti billionaire propaganda, so a lot of people, especially teenagers, will need it explained to them that being a billionaire isn't so bad now. The Marxist-Leninists will all be saying that Cyborg Bernie Sanders is an evil billionaire, and us reasonable leftists will be explaining that a billion dollars is just what it costs these days to own a residence in your home state and also in DC, which is necessary for working as a senator.
What we'll really need to look out for by then is the trillionaires. Good for nothing parasites. There's no excuse for one person to own a trillion dollars while there are people living on the streets who can't even afford a measly ten thousand dollars for a cheeseburger meal.
So inflation is 3-8% every year, so the equivalent of 1m today will be 19m-2.1b in 100 years
Since the target is 2-3% it's perhaps more likely to be 19m
Really shows how dumb saving for retirement is for the plebians
Only if you don't invest. Hell, if you only want to slightly beat inflation there's a guaranteed way in the US, TIPS and I-bonds. Does assume the government hasn't collapsed, but that kinda applies to all retirement plans.