It's an inflation phenomenon, it largely stems from the explosive growth and centralization of the government post-WWII and subsequent abolishment of the gold standard. You exchange labor for Nancy Pelosi's (alternatively replace your preferred congress person) Chuck-E-Cheese tokens and those tokens are being created out of thin air (treasuries being the gold replacement) to finance whatever war, bureaucracy and any other boondoggle imaginable.

Now instead of getting tokens that are constrained in their scarcity (gold based), you've got constantly depreciating ones, which means your employer can pay you less every year without lifting a finger. The playing field is in their favor in an inflationary environment cause it's now the laborers' burden to search for new employment if they want a raise.