The idea that any working class boomer could raise a family/ own a house on a single income is a myth. That was only true if you were a man, and happened to be white. The federal government built the interstates to the suburbs, the GI bill loaned the money to buy the house, and sent you to college. All to the exclusion of POC and women.
Even the labor unions told black men that you couldn't be in a union without a job, and couldn't get hired unless you were in a union. This "golden age" economy was also when a divorced woman couldn't get a bank account, an apartment, or a job.
The capitalists weren't sharing more wealth, they were sharing with fewer people.