We are using different terminology.
The bottom 80%'s share of the national wealth has been dropping and the bottom 80%'s share of the income has been dropping.
If the wealth had continued to be shared as it had in the past, the effective middle income would be closer to $70,000 per year instead of $50,000 per year.
If you look at things as a "checkmark", it looks better. You have a TV, Refrigerator, etc. as long as you can keep a job.
But the lifespan of all the appliances is a third of what it was. Repairman took a 31 year old capacitor out of my air conditioner last month. He said, "What I'm replacing this with won't last 7 years."
At amusement parks you have two ticket prices. The $70 tickets that provide much lower service than used to be provided and $250 tickets where you get much better service (cutting to the front of the line, even reserved ride times).
Clothing is less durable and of lower quality.
Food is less nutritious and of lower quality. (Go buy some real cage free eggs like everyone used to get back in the 70s. Compare them to supermarket eggs. When scrambled the supermarket eggs are almost white these days.) Real eggs of the same quality people used to get cost $5 per dozen.
Beef becomes less affordable every year.
The beaches are divided into uncrowded luxury areas and smaller and smaller grossly overcrowded - not even "free" areas. You have to pay $10 for what used to be free.
Television shows used to be 52 minutes of content. Most TV shows 42 minutes of content and one recent show was 39 minutes of content.
You can buy a microwave- yup- $80 to $200. It will last under 7 years. If you buy a microwave made the way they used to make them- its $1000.
And so on.
I'm not saying it's all bad. I'm just saying we are the frog in the stew pot. The change has been so slow, we didn't notice it. And young people don't even know what they've lost.