There are ways where an employee that works 40 hours has less than half the impact than someone who works 60 hours. But plainly high quality code is not one of them. It works when you get a block of intense focus time and then go off to spend a lot of low-energy time in a breadth of business matters, including casually learning how to do your job better.

In the first year or so it often doesn't make an obvious difference, because you just seem to produce as much hard output as the others, but you have a faster exponential growth curve. The combined quality and quantity of your work can outpace others. If you're both talented and lucky, at some level of depth and breath you may become the best, help the company corner a market, at which point the impact of your labor becomes superlinear to your efforts, which makes the difference even more obvious.

The main problem is that this difference in impact is primarily captured by the employer in most places. Employers are either oblivious to the difference or short change the better employees because they only have to pay everyone market rates, as outsiders are often in an even worse position to distinguish the quality of the two types of employees. Maybe you became L7 by making much more than 2x as much impact as an L6, but you only get maybe a 30% pay bump.