Yes, but you could also say that it was created so that advertisers stop doing complete nonsense like tracking pixels and other roundabout ways of accomplishing the same thing in ways that are sometimes (often?) detrimental to the user.

Sure, it's a form of capitulation to advertisers, that doesn't necessarily mean that it doesn't benefit the user.

If advertisers are going to be doing that stuff no matter what, corralling them has advantages. If anything, it makes creating an extension like OP's a lot easier than playing whack-a-mole with a litany of random techniques.

Sure, which is exactly the rationale for disabling it.