In contrast, the real wages of top professionals such as doctors and lawyers has more than doubled. The pay of many relatively unskilled and semi-skilled workers (including bakers, forklift-truck drivers, packers and bottlers) has actually fallen in real terms since the 1970s.
Yes, that’s what happens in an economy.
As technology changes the demands for the labour to perform certain tasks changes. Wages then change to reflect the differences in supply and demand for those certain skills.
Since the 1970s baking has become ever more mechanised: pallets reduced the need for forklift drivers. Similarly with packers and bottlers, we’ve mechanised more of the task.
We just don’t need as many of them as we once did.
In any and every economy with any form of dynamism technological change will change the wages of some forms of labour. To complain about this is to be Canute, or as the Norwegians misspelled his name, a Cnut.