Your very first sentence sums up the problem: In my experience there is nothing really stopping a determined woman from progressing at the same rate as a man before children..
The problem is the very large number of not-terribly-determined men who will also progress at this rate. Why do women have to be "determined" and men just have to turn up?
The structured career paths in investment banking, law, accountancy etc theoretically should, as you say, not impact women. But they still do. eg, "complete every project to a high standard" - I completely agree. BUT, there are differences. Eg... which projects? The men are more likely to be allocated to the high profile, highly profitable projects and desks.
I did some work for a law firm a few years ago that had done some work on their gender pay gap report. when they looked at the data, pay for men and women was largely equal. But when they looked at bonuses, they saw there was a difference. This seemed odd but at first, they thought, "well, bonuses are about performance - billable hours in particular, as well as performance reviews and the reality is that there are more women working part time, or who have caring responsibilities so that must be it." But then they looked at the data a bit more closely and they realised this discrepancy in bonus was happening pretty much from day 1 and that, even adjusted for part time work etc, was happening throughout the firm, not just at the point at which women's caring responsibilities were ramping up.
So they took another look. And lo and behold, at most levels, there were disparities in billable hours. They thought, "so what, evern 24 year hold women are choosing to work fewer hours when they don't have children, what's happening here?" So they went to talk to the women. (bearing in mind the discrepancy wasn't necessarily huge but still there). And it turned out that many of these women were more than willing to put in the extra hours, but they weren't being allocated the work on the really big, chunky, juicy projects that required almost infinite amount of billable hours. (I have a memory of also being told that many were taking on more non-billable projects but I feel like that COULD have been another client, not this one). [++ side point: I also have a sneaky suspicion the women were just more efficient! 
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Then they took a look at the subjective part of the performance reviews - ie feedback from partners and managers. And again, interestingly, they saw that while the overall curve was similar, the women's curve was shifted to the left... ie similar percentage of top performer vs low performer relative to the female cohort BUT, that the top performers were, on average, slightly less high performing than the male top performers and the low performers were slightly more low performing. How could this be? It made no sense - surely the breakdown should be similar between men and women? Again, they tried to dig into this. And found that partly this was the same issue as the billable thing - ie that the higher profile, chunkier work tended to get higher performance ratings from senior partners so of course, that was the men. Plus some more nebulous factors around the fact that women would just consistently get marked a bit lower (not allowing for the super super high performing women but of course, those are the ones working 3x as hard, figthing 5x as hard but still only on a par with the top men).
So in order to fix their gender pay gap, even at the relatively junior level, they had to improve the performance metrics and remove bias. And then they came up against another challenge - when they told the senior partners within various practices that the work allocation process was a problem, they got pushback. So within a year, those practice groups that had accepted they needed a more data-driven work allocation process (done by a centralised team based on the data available about the individual lawyers' skills, experience, workloads), they quickly saw billable hours equalise and bonuses start to increase. But for the practice groups that refused, the bonus gender pay gap remained. In part, they solved for this by simply shifting the entire female cohort up the curve, but it was an ongoing challenge.
In many ways, I'd argue banks, law firms, consultancies are often the worst, still. Yes, women can succeed. But they still seem to have to work harder and play by traditionally male rules more often.
[INcidentally, a few years before this, another law firm client I worked with did some analysis on the language used in performance reviews for women vs men... blow me down with a feather, all those characteristics that are so often portrayed differently for me and women were there. Assertive men, aggressive women. Ambitious men are goal-driven, ambitios women are "competitive". Men are passionate, women are emotional etc etc. They also found that male performance reviews focused on work but women's often focused on softer skills, subtly undermining the women's performance at revenue-generating tasks.]