OP correctly points out that productivity and monetary value created are non-linear and extremely problematic to measure for the software development profession

OP correctly points out that productivity and monetary value created are non-linear and extremely problematic to measure for the software development profession. More importantly, OP reminds us that software dev is far from being the only career for which this is the case. In "convex" work, as michaelochurch calls it, most of the time you are actually contributing less value than you are being paid for, if you are drawing a salary. Some days your work might contribute no direct value at all, or even subtract value. But occasionally, by creating something new that itself generates value, you can contribute exponentially more value than you are being paid for. But you still only get your salary. Because taking a salaried job is selling your downside risk along with the potential upside reward to buy income stability. A "10x developer" isn't someone who writes 10x more LOC or even contributes 10x more valuable software on a daily basis. It's a developer who is able to occasionally make those big breakthroughs that you hope for when you're doing convex work.