I think the issue is that you measure productivity as in quantitative physical output instead of in value as driven by supply and demand. Absolute value increases due to inflation even though the supply/demand ratio is the same.
Re:Baumol Effect
by JumpCrisscross on Saturday October 17, 2020 @11:22PM
(#24815295)
> Absolute value increases due to inflation
For a meaningless definition of absolute, where it coïncides with “nominal,” yes.
I imagine streaming services were not a thing back then.
Also you make fair points in your comments but you confuse the example for the argument. Replace 'String Quartet' by 'waiter' or 'child minder' if you prefer.