As tech increased, it increased the number of bills that people had to pay. If the ONLY thing you own is a home, you only need a relatively small amount of money to meet your needs. If you have to have a home and a car and a tv, then you need more income to support an 'average life. If you need a home, two cars, 3 cell lines, an internet service, 200 channels on the tv, etc then it tends to stretch that income quite a bit more.
Our 'needs' have climbed and expanded so dramatically in the last 60 years that the 'necessities' cost a much higher percent of our disposable income. When you add other factors to that it means that a 'good' income simply isn't going to leave over as much discretionary spending as it used to.
OK, terminological quibble, then we'll get to the meat. If it's a necessity, in quotes or not, then it isn't discretionary income.
There are really two questions about the "wealth of the nation." Back to the old pie analogy. How big is the pie, and how is it divided? All of it belongs to somebody. Forget about government "handouts" good or bad. How much of the pie do you get, and how much should you get? That's the underlying question of wages, tax policy, investment strategies and income, all that stuff.
That's the "how is the pie divided" part. How big is the pie has two features: legitimate increases in the actual size of the pie, and debt that will never be paid. The easiest way to increase the size of the pie is to print money and hand it out. Of course, every time that's been tried, it has ended in catastrophe. Maybe we're beyond that. I doubt it.
We can quibble endlessly about the means by which a person gets money. . . wages, government handouts, reductions in government (or debt-service) takings. What's important is how much money, as a share of the total pie, is each person getting?
My view is that every adult should get enough to pay for a one-bedroom dwelling, furnishings, mechanized transportation, three decent meals a day, clothing, household and personal-care supplies, and a reasonable entertainment budget. And the government services that we benefit from. And everybody should be required to work to get that, even to the point of making up non-productive work for those who are genuinely physically or mentally incapable of productive work. That should be, oh, call it a third of the pie, I won't argue about the number. Another third should be rewards for those who do more productive work, either by working more hours or producing more value with what they do. The last third is money unavailable for immediate spending because it's at work producing more money (investment, capital goods, etc.).
This may seem very simplistic and philosophical, but I've found that in many cases, people arguing about the tax rate, or wages, or corporate income, don't really have a firm grasp of this underlying structure. I'd like to hear your thoughts on what I've said here, and make sure we're on the same checkerboard before we begin debating the moves.