To be fair, they didn't say they're working one day a week, they said it takes them only one day to provide equal value to what their teammates achieve in one week, a value that seems to meet their company's expectations.
FAANGS employees are salaried, and not paid by hour, because you are compensated for ROI. If it takes you one hour and you bring in lots of value, that's still a good deal. On the flip side, you could also work 60 hours week if that's what it took you to meet and exceed on the value expectations.
Still agree with much of your comment though. Since they're complaining about the situation, something does feel off.
Ya that's why I still agree mostly with OP in this particular case it seems something is off.
I just wanted to explain that with software, a small effort can deliver huge returns. So the idiom of: "Don't work hard, work smart" is in full effect. If you can deliver on the expected business value with less effort on your part it is still a win/win scenario. A business who'd replace you for someone who fills up all 40 hours would not necessarily gain anything, in fact, might lose on ROI. Hours put into software does not translate directly into the output delivered.
And, there's only so much creative juice per week you can deliver on, so that cleverness of solutions you can come up with, and those good ideas you have which don't take very long to implement, but deliver big returns, you can't necessarily just be asked to come up with them twice as often by working more hours either. In fact, sometimes those come by taking a break, a step back, getting more rest, etc.
And maybe since we're on the topic, I've had a fare share of jobs prior, server, construction, military, and yet nothing drains me more than software engineering at the end of the day, even if it was only a 6 hour day. There's something about just thinking all day and discussing heavily all day that is super draining mentally. Where other jobs I've had that were more physically demanding tired me, but in a good way, that almost energized me in my off time. The mental work is hard.
FAANGS employees are salaried, and not paid by hour, because you are compensated for ROI. If it takes you one hour and you bring in lots of value, that's still a good deal. On the flip side, you could also work 60 hours week if that's what it took you to meet and exceed on the value expectations.
Still agree with much of your comment though. Since they're complaining about the situation, something does feel off.