Pay gap for men and women only starts mid career. But this isn't the 80c on the dollar pay gap (that's median male earnings vs female). It's usually in the 90c range (iirc 93c is the median and even Uber found a pay gap in this range). There's also the glass ceiling. But neither of these things have a smoking gun to them. They are hard to solve and going to require a lot of us to start talking about them. So I'm not sure why we only discuss median gender earnings, which isn't a great way to discuss fairness. It's especially bad when we discuss median gender wages as if they are controlling for variables (like the 90c+ gap does, which you see in part of this data). But don't let the bad discussion of median earnings prevent a discussion over the actual phenomena that exist.
Edit: there's a lot I didn't say here, I'm glad others are adding more. But let's also try to be nuanced because it is a complicated topic. I also wanted to plug a podcast "The Pay Check" which goes in depth into these issues, including attempts to solve them. It's from the perspective of economics (by Bloomberg) and discusses all the common misconceptions like child rearing.