Says more about the power of investment over 35 years than it does about bicycles, really.
I haven't taken more than a glance over the grandparent's calculator, but this shouldn't be too hard to estimate. The Edmonds TCO calculator gives the five-year cost of ownership for a two-year-old base-spec Toyota Camry (as generic a car as I can think of) at $37,196, inclusive of gas, maintenance, etc. Assuming you buy an equivalent car every five years, that comes out to a monthly cost of $619. If you instead invested that money at a five-percent rate of return, then after 35 years of contributions, the resulting fund ends up being worth a hair over $700,000 -- not enough to fit the "millionaire" tag, but close.
There are plenty of less obvious costs associated with riding a bike instead of driving a car, of course -- and some less obvious benefits. But the moral of the story is obviously "invest your money".
This is a misleading calculation, since it assumes that the car has zero economic value over and above the bicycle. Whereas in fact there's a very large value for many people, in terms of being able to move heavy things, go on vacations, get to and from work etc etc.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.