Even if we assume that saving that much is possible, the math only works if you're up for living a lifestyle costing 33% of your current earnings for the rest of your life.
It is, but usually only to the extent of "spend less than you make" and "save X% of your income," where X is significantly less than 50%. Only until you get to the FIRE community do you see people start talking about 50-60+% savings rates.
I see it all around, like "housing should be around 30% if income" or a budgeting system like 50/30/20 (needs/wants/savings&debt).
I just think the concept of decoupling them isn't something people quite appreciate until you get really into personal finance. When going from college into a career your salary can double quite a few times and if you can keep you living expenses restrained it's a lot easier than a decade later trying to pull back and pay down debt.
That's one of the main ideas behind the more extreme variants of FIRE - live like you lived when you were 25, keep getting raises, save 80-90% of your post-tax income. Also, learn to cook, fix things around your house, fix your car, grow some food etc and you'll be freed from from jobworld in 5-10 years max.