I certainly agree that there are many important aspects to software development, other than just code.
But I don't want to confuse the point, and accidentally be thinking "plagiarism of code isn't important, because code isn't important" (or the limiting factor).
For one reason, code is important, and valuable...
There's plenty of evidence throughout many types of software development to suggest that a lot of money has to be plowed into simply producing bulk of code -- excluding domain or market understanding, requirements analysis, holistic system design, etc.
A typical growth startup wasn't in a hiring frenzy for great analytical minds, but simply to scale up production of raw bulk of code (and connecting together legally-obtained off-the-shelf pieces). And they were often tracking quantitative metrics on that bulk, and consciously aware of how much all those code-monkey salaries were costing on the balance sheet. They paid it because code bulk was very necessary, the way they were working.
There's also plenty of evidence of the popularity of copy&paste reuse for many years. Including from StackOverflow.
Copying entire projects and subsystems has been much-much less common, partly due to the aforementioned not wanting to get caught doing it. But "AI" laundering is paving the way. See all the blog posts and videos about "I created an app/game/site in an hour with AI".
We can also look at startup schools of thought, where execution is widely regarded to be everything (ideas are a dime a dozen). There is plenty of thinking that churning out code is one of the most time-consuming or frequently-blocking parts of execution.
In both startups and established corporate environments, there are normally big lags between when a need for specific code is identified, and when that code can be delivered. Doesn't that look like a limiting factor, or at least it must be important.
I think that's enough reason that we not dismiss the value of code, nor dismiss the importance of plagiarism of code.