If I'm implementing literally the same stuff at the same time then I bet that's a massive copyright violation.
You have to take pains to avoid contamination when reverse engineering a product, for example, and that doesn't even involve the original staff.
Seems that your argument could also be used to justify lifetime noncompetes. If I work for a company, gain experience, then go work for another company, they're getting the benefit of all of that experience without having to pay for the years it took to obtain it.
But your next company is getting your prior experience, which becomes more out-of-date every day, not your up-to-the-minute experience on what might be an actively competing project.
doesn't negate the problem stated as whatever the experience is, it's value is non-zero. Hence the benefit to later employers is also non-zero (could be argued) at the cost of earlier employers
the problem is more specific than the second employer getting non-zero value. It's getting ongoing value, under the table, direct from a present competitor -- harming the relative competitiveness of the first employer.
The value of this, of course, depends very much on the specific industry and project. It doesn't really matter if your guy who builds generic websites for your clients also builds generic websites for a competitor's clients. That doesn't materially hurt the first employer. But it can matter a lot if your guy who you are paying to develop cutting-edge algorithms is deploying those algorithms to the competitor you're trying to beat. Instead of gaining an edge worth $X per year, your company instead gains only part of that advantage because at least one competitor is cutting into it.
You have to take pains to avoid contamination when reverse engineering a product, for example, and that doesn't even involve the original staff.
Seems that your argument could also be used to justify lifetime noncompetes. If I work for a company, gain experience, then go work for another company, they're getting the benefit of all of that experience without having to pay for the years it took to obtain it.