Google likes to fuck with basic browser functionality for some reason. Scrolling, sometimes also how “click” intents through touch are triggered (that is, using js listeners for touch events instead of watching for the browser to communicate a “click” on an element; this does usability-killing shit like make a touch-to-stop-scrolling get interpreted as a click on whatever happens to be under your finger). I have no idea why they do this, but they do it a lot, so it must be a cultural thing.
And I don’t mean like some designers will highjack scroll to deliver a different experience like slide-like transitions or something (which may or may not be, differently, awful) but they’ll override it just to give you ordinary scrolling, except much worse (as on this page).
Seems like a lot of work to do just to make something shittier, but what do I know, I probably can’t implement a* on a whiteboard from memory or whatever.