But how is there this weird curve that 40 years ago, there was an equivalent sustainable rate of essentially $24/hr or something- but now that businesses can't

But how is there this weird curve that 40 years ago, there was an equivalent sustainable rate of essentially $24/hr or something- but now that businesses can't sustain it? It seems that companies and the economy keep growing, but for some reason we haven't kept up with the purchasing parity of lower end workers