You can run a web server by responding to every request by hand-typing the response, too. But you couldn't realistically run one-one-millionth the modern Web that way. You can't have global-scale e-commerce that way, et c. Some things that technically could work that way, can't actually—it's too slow, too expensive. This is very much one of those "quantity has a quality all its own" things. Increase the productivity of every astroturf-poster or propaganda-front-news-site manager a few hundred times and that's a big difference.
> I am as concerned as the next guy but throwing the towel already seems a bit premature?
Where'd you get throwing in the towel? I do think we're (especially the US) really unlikely to do what we need to in time, in part because measures that are probably necessary to defend against this are themselves risky and rather unappealing. But we might.