Fair use isn’t a right, it’s a defense available for infringing on someone else’s [copy]rights. That distinction is why the act you’ve quoted very precisely say

Fair use isn’t a right, it’s a defense available for infringing on someone else’s [copy]rights. That distinction is why the act you’ve quoted very precisely says that it is “permissible” for you to quote excerpts [for specified uses] while it emphatically does not say that you are “entitled” to quote excerpts… by your reasoning an author would HAVE to provide you screenshots on demand simply because you asserted fair use. I hate that they’ve stooped to stopping a screenshot — note, that they haven’t stopped you picking up a camera, though — but they absolutely haven’t infringed on any of your rights, in any currently extant country, by doing so.