In all of these cases real incomes grew enormously. Yes, a big part of that was starting from a low base after the destruction of WWII. But I'd argue it was also a strong consequence of the technology of the time: the was an explosion in consumer goods enabled by new tech, but companies still needed lots of employees to create these products. In the past ~25 years I believe tech has instead allowed more wealth to accrue to a smaller and smaller subset of people.
Yes, all fueled by ridiculously abundant/cheap oil. This is something that might not happen in Earth's history ever again, not to mention the climate change issues (which at least weren't clear until much later, 80s rather than 50s for oil depletion issues).