Actually "Copy as cURL" adds much that is not required. In some cases this can be useful. However if all one cares about is what is actually needed to succesfully request a resource using HTTP, then "Copy as cURL" always includes too much. It includes "things that dont matter".
HTTP is more flexible than "Copy as cURL". There are things that can be done with HTTP that cannot be done with cURL.
(NB. I am not a developer. I am not writing software for other people. I do not profit from online advertising. I use a text-only browser with no auto-loading of resources and no Javascript engine; I never see ads. Been using HTTP/1.1 pipelining, which all major httpds support, outside the browser, daily, for many years. It works really well for me; I rely on it. As such, I am not the appropriate person with which to debate the relative merits of HTTP protocols for developers who profit from online ads served via "modern" web browsers.)
HTTP is more flexible than "Copy as cURL". There are things that can be done with HTTP that cannot be done with cURL.