By your numbers, someone going straight into the workforce could save about $50,000 each of the first four years the peers are in school, amounting to ~$2M by the time the person approaches retirement age. That is compared to the ~$3M that could be made by the gains in post-graduation income by retirement. However, the cost of the $140,000 education by the time you reach retirement is ~$1M so you have really only just compensated for the education with the higher income. And all that assumes that you will be able to earn more with said degree. While it certainly happens, I am doubtful that it holds true for all graduates. There is a lot of financial risk there, for what appears to be little to no monetary reward even when you do win.

With that said, there are a near infinite number of positive reasons to partake in a post-secondary education. It doesn't need to come with better jobs and higher incomes to make it worthwhile. I find it rather sad that many feel we have to resort to showing higher future incomes to even justify going.