Of course, that is only talking about wide-scale scanning. If you're only looking to scrape a single target, for whatever reason, then having an instrumented headless browser will greatly simplify things. Headless Chrome should be more efficient than running it in a (virtual) framebuffer. Plus the whole setup for a powerful crawler is reduced to "install Chrome, start it, point $crawler at the API endpoint". My guess is that we might see turnkey crawling / automation tools appear where you supply a list of URLs and the library + Chrome does the rest. Then, browser-based large scale scanning will be within everyone's reach, only limited by their resources.
Background: I created https://urlscan.io which will simply visit a website and record HTTP interactions (annotating the resources with some helpful meta data). I've been preaching the power of headless instrumented browsers for the better part of a year now ;)