I think this design looks clean and is convenient to use but practically impossible to discover without the help of google. It feels like the developers are deliberately discouraging the use of sleep.
- There are plenty of space in the drop down menu, so why not add another button for sleep?
- After pressing the power-off button, a prompt pops and lets user select between reboot and power-off, which is a classic design dating back to Windows 9x, so why not add a sleep or hibernate option there?
Is there a email thread that can explain for the rationale of the current design?