And it was hardly the only one around at the time, many other libraries in many other Greek cities with Pergamum probably being the most notable.
The same can be said about the internet archive though.
Can it? I don't know of any other public internet archive anywhere near the scale of the Wayback Machine.
Its not an argument on the scale of the operation but rather if alternatives exist. I am merely stating that burning down a library is not less of a loss if an alternative exists, especially seeing that you'd need to find the new archive and get awareness out about its new location.