Lowering consumption during working years also has the beneficial effect of requiring less savings to maintain that lifestyle in retirement. Otherwise, people will experience a "cliff" where they go from consuming a lot while working to much less in retirement. For most people, the goal is to maintain standard of living in retirement. Of course it is easier to maintain a standard of living that costs less money to begin with. The good news is that the backpacking lifestyle is minimalist by nature. Not everyone takes the minimalism of the trail into "real life" but those who do will be able to retire sooner than others.
I've never believed that higher levels of consumption leads to happiness. Some of the most miserable people on earth are very rich and consume a great deal and it still doesn't make them happy.