That number makes absolutely no sense considering how much more basic stuff like housing is now.
Income going up does not actually mean anything without taking into consideration that people are less likely to be able to buy a house now than 50 years ago.
Exactly. If incomes increased at the same rate as housing did, then people would be much richer today than they were back then. It's why inflation uses a basket rather than just cherry picking a single component of the basket. If you want things to look bad you use housing. If you want things to look good you use potatoes. If you try and be fair you use a basket.
Income going up does not actually mean anything without taking into consideration that people are less likely to be able to buy a house now than 50 years ago.