Yes, basically it comes down to racism and classism, and a bit of the fight against communism.
There used to be racial covenants that ensures racial segregation. As soon as those were rendered illegal, people started zoning for "public safety" and such. The original decision (Euclid?) that rendered zoning legal explicitly states concerns about lower income people degrading neighborhoods if multi-family residences are allowed.
And as soon as you start allowing such restrictions on what sort of construction is allowed, you start outlawing small business next to residences. And home buyers appreciate these restrictions because there's chance of a business growing and causing more traffic and "outsiders" (those that can't afford to buy a huge parcel of land) coming into their bucolic suburban life.
Subsidized FHA loans were also envisioned as a strong anti-communist play; who would fall prey to the temptations of socialism if they own their own home and can use it to keep out non-whites? (Redlining restricted these subsidized mortgages from being used for any home that had a chance of becoming racially integrated.)
The rise of the automobile and destruction of commuter rail lead to a ton of land accessible to people who worked in cities. And in conjunction with the exclusionary zoning that was used to protect the capitalistic gains of property values, the idea of mixed-use zoning became antiquated and counter productive to financial and social interests.
So a century later, we are finally realizing the massive health costs, societal costs, and economic costs of our unsustainable suburbanization; infrastructure is aging out without the tax base to maintain and rebuild, and the suburbs--filled with wealthy residents paying lower taxes--have drained the economic centers of cities, while those wealthy suburbanites benefit from the commerce that high density cities enable, and which low-density suburbs disallow.
We have subsidized an unsustainable style of living for the white middle class, and as white middle class boomers have benefitted, they have declined to allow for basic investments in the future that would extend prosperity to future generation.
This, I think, is the story of the decline of the American empire, just as much as mismanagement by a fascist-leaning a factual political party. During the decline of the USSR, even with massive amounts of state propaganda and misinformation, at least they were able to muster state power to clean up Chernobyl. I'm the twilight of the US, we have hollowed our our scientific institutions like the CDC and FDA because they don't serve the political goals of the ruling political class, and we can't even muster a response to a pandemic that countries with widely-regarded corrupt governments such as Italy have dealt with handily. I think this rot comes from our racist segregation which lead to our poor century of city planning.
(This, of course, would need several books to fully justify my wild claims, but one book that starts to is The Color of Law by Richard Rothstein.