I don't think parent meant to say that the technology behind Facebook is trivial. Just that it's trivial when contrasted with a bunch of technologies that are a

I don't think parent meant to say that the technology behind Facebook is trivial. Just that it's trivial when contrasted with a bunch of technologies that are at best in prototype stage. 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.