In contrast Facebook is largely just a couple of web forms and some Big O problems at scale.
Yes, and Steph Curry is just a guy shooting a ball in a basket.
A decade-long life extension or growing meat without animals would both probably involve more "Hard Tech" style innovation than building Facebook.
Other observations are IMO less pat. E.g. designing cheaper/better sensors could be either harder or significantly easier than building a Facebook. Depending on the type of sensor and the cost improvement.
Facebook is doing more than that. Mark recently claimed that they are working on "a world-class News Feed, and a world-class messaging product, and a world-class search product, and a world-class ad system, and invent[ing] virtual reality, and build[ing] drones".
Based on the glaring flaws in the base product, I'm unconvinced it has the smarts to do any of those things well.