This approach can stop very basic scripts, but the claim that “99.9999% of scrapers can’t execute JS or handle cookies” isn’t accurate anymore. Modern scraping tools commonly use headless browsers (Playwright, Puppeteer, Selenium), execute JavaScript, support cookies, and spoof realistic user agents. Any scraper beyond the most trivial will pass a JS-set cookie check without effort. That said, using a lightweight JS challenge can be reasonable as one signal among many, especially for low-value content and when minimizing user friction is a priority. It’s just not a reliable standalone defense. If it’s working for you, that likely means your site isn’t a high-value scraping target — not that the technique is fundamentally robust.