Yup. GP is definitely exaggerating how likely it is, although his larger point that in this era, working in the game industry is an explicit choice, because there lots of other options out there for devs, that point still stands IMHO!
Simply put, if you save half of your take home, your passive income will approach your living expenses in roughly 10-15 years. And that even with a conservative draw of 3%, you can start to live off that money without touching your principle. There are a lot of assumptions about inflation and not getting stuck in a long bear market, but it's still a fairly solid way to look at how our spending keeps us tied to our work. The really big takeaway from MMM (who lately has been seeming more and more out of touch sadly), is that every dollar you remove from your budget works double, in that it helps you grow savings, but also decreases the amount of costs interest you need to live on.
Compound interest is something that more people should really understand.