Note that real median PERSONAL income, which doesn't depend on family size or the number of incomes per household etc., tracks real median family income almost exactly.
So yes, the above graph does give an accurate picture of income trends.
And note that although income has increased, this chart shows that in real terms, the median American was only about 44% richer in 2019 than in 1974.
Meanwhile, real GDP per capita was 120% higher.
That's called "rising inequality", folks.