I'm also tired of seeing this mythologization of the USA's past.
The specific observation is that large chunks of the population have lost the willpower, grit, or whatever to solve their own problems.
Back when the US started, people came over here and by sheer force of will made their way in the world.
Back when the USA started... it was genocide and rape of lands. Full stop. "Came over here and by sheer force of will made their way in the world" literally means "Came over here, slaughtered lots of natives, and enjoyed rapid expansion over their territories full of unexploited resources."
You associate FDR's policies with the decline of this grit culture. But let me point out a different association. In 1912, contact was made in California with who is considered to be the last Native American to have grown up without any interaction with the western world. That's a pretty solid landmark for expansion in the New World. The New Deal was only about 20 years later. I'm much more inclined to believe that hitting the limits of expansion into native territories has more to do with the decline of settler grit than FDR's policies did.
Today's situation is not at all comparable. Human population has roughly quadrupled since 1912. There are no more frontiers. There is nowhere to expand for access to resources that are not already claimed. There are wild places left, but they are protected for good reason. The environment is collapsing in a dire way. A third of all wildlife is in danger of extinction. Insects as a global biomass have declined by 80% in the past 30 years, and the remainder is disappearing at a rate of 2.5% per year. What's left must be carefully managed by collaborative agreement for collective interest. If that's not the realm of government, then I don't know what is.
I also don't think the idea that everyone should just run their own businesses instead of complaining about wages is very practical. I honestly don't understand the kind of world you envision by that logic. There are too many goods/services that are better provided for by a large organization than a small one, or are beyond the reach of a small business completely. And unless you imagine most of the working population running one man operations, the problem of wages is still there. Just more of a nightmare, because there's many times more employers who need their asses kicked to pay their people. Wages are a problem that has to be addressed no matter what, and they're only addressable by means associated almost exclusively with leftist politics -- unionization, strikes, government intervention, etc