Day 1: John has $10 and Joe has $100
Day 5: John has $11 and Joe has $250
Day 100: John has $15 and Joe has $1000
They certainly both have more than before, but one of them is much better off (especially if there is some form of inflation in play).
Also, blue collar wages have been largely stagnant or declining when measured against inflation (a very important point) since ~1980 while conversely white collar job incomes have been ballooning against the same measure. In particular, Executive compensation is utterly off the charts comparatively. When tax discount structures that vastly favor investment income over real wages is taken into account, the gains become even more stark (that is, the amount of income that can be retained v must be spent or is taxed).