This is sadly true, but forgets the context. FDR, by far the most popular president in US history, talked about the "four freedoms" in 1941.

FDR was a class traitor, a class warrior, and a smart negotiator. If FDR hadn't died, these rights might have actually been implemented.

But FDR did die. So with the Taft-Hartley act, the 22nd amendment, etc. the next several decades TPTB kicked FDR's ghost back to the gilded age, setting up the 70s-00s of deregulation that have truly fucked the US and much of the world with it.

That book you found is - sadly - "the path not taken" because the world has far too few FDRs and far too many greedy rich assholes.