The settlements of the big financial firms in NYC showed the issue in a nutshell; fill the slots with the correct quota of females or pay millions - and hire a “chief diversity officer” (anyone but a straight white guy).
I was born in the 70s so can’t speak to practices of the time; I’ve worked in the environment of 60% female college classes that still result in underrepresentation in STEM.
Again, the underrepresentation in STEM IMO doesn’t mean a whole lot. Most women just have a) very little interest in actually becoming a techie and b) working either lots of overtime or choosing a career path to optimize their direct earnings. The latter is not an evolutionarily winning strategy for them and doesn’t tend to optimize their lifestyle or liiving standard. Now that I think of it, it wouldn’t surprise me if there was a co.parative mismatch between male and female accounting students and I guess workers. The women may be more likely to come out of and aspire to the bookkeeper model in general and the men to the CFO or big accounting firm partner mode. Relatively more able women to go into liberal arts or law or medicine.