There was this scholarly article from Pamela Samuelson and Suzanne Scotchmer

https://yalelawjournal.org/pdf/200_ay258cck.pdf

which, as I recall it, suggested that the copyright law effectively considered that it was good that there was a way around copyright (with reverse engineering and clean-room implementation), and also good that the way around copyright required some investment in its own right, rather than being free, easy, and automatic.

I think Samuelson and Scotchmer thought that, as you say, costs matter, and that the legal system was recognizing this, but in a kind of indirect way, not overtly.