This obsession with the time put-in (either way) is quite silly to be honest. It's a notion inherited from the blue-collar industrial factory labor. If you're working on really hard problems there's no way you're putting in 12 hour stretches. Your diet takes a hit, your sanity takes a hit and so does everything else.
Japan tried this non-sense for a while (colleagues told they used to stay on till 11am !) only to completely fail at all three software revolutions (web/smartphone/ai). China obv. has had much better success, but I don't think this is sustainable. The central-banks in these countries operate in the war-economy mode which can heat things up a lot and work very well, but I think social-burnout effects are quite real.