Very few websites are truly static. Something like a Wordpress website still does a nontrivial amount of compute and DB calls - especially when you don't hit a cache.

There's also the cost asymmetry to take into account. Running an obscure hobby forum on a $5 / month VPS (or cloud equivalent) is quite doable, having that suddenly balloon to $500 / month is a Really Big Deal. Meanwhile, the LLM company scraping it has hundred of millions of VC funding, they aren't going to notice they are burning a few million because their crappy scraper keeps hammering websites over and over again.