I found the book to be a disappointment. It now seems to be used more as a recruiting tool for activist volunteers. It's philosophy, not personal finance.
Personal Finance is the control of your expenditures is it not? You can live within your means or you can try and maximise your returns. His book to me was very clear, find out what you feel is important, track and budget it and start saving money to earn interest that will pay for those expenditures.
I don't know how many people really want to live a life as what they are implying you would end with, but for the most part inflation for what is essential in America is very low assuming you own your house. Furnaces and Air Conditioners are far more fuel efficient now than any increase in the commodities used to run them. Today's best Nike shoes are no doubt more comfortable yet do they protect feet any better than the standard gym shoe of 35 years ago? Those can still be bought at a fraction of the price of the top Nike shoes.
There is a reason the average home has increase in size from 1200 to 2100 square feet over the past decades. Real life living standards have improved. Keeping up with the Jones's is the main source of inflation in America today.
For individuals living on such a simple lifestyle interest income is best - why if you feel that too much of the world is spent on unnecessary items would you put your money into an investment that counts on a continued surge in spending on those items.
Personal finance is how you control your money, money is merely a stored unit of your time. Therefore personal finance is a control you exercise of your money and your time.
The range in America on the spending side goes from the Unabomber at $300.00 per year to the millions per year spent by Donald Trumps always doing the first class ride. Inflation rates at each level in between are very definitely personalized and not the CIP.