1% real income growth per year is still fairly substantial IMO. Over a 41 year career, your purchasing power goes up by half, yet that's treated as "stagnating" which implies something far worse than 1% per year.
Those of us in the broad swath from 10th to 99th percentile don't really compete for those things that are purchased by the top 0.01%, so I basically don't care how fast their incomes grow, nor how fast the prices of caviar, ski lodges in Jackson Hole, etc. grow.
I care about food, housing, transportation, and education. In competing for those resources, there's fairly broad equity in the charts in the vox article (realizing that people don't stay static on that chart).
The opposing term is "nominal income growth" which does not account for inflation.