Monitors only* turn themselves back on if they're not explicitly turned off using the power button. Also, vampire loads aren't really a thing anymore. You can't even save $1 a year that way on any halfway modern monitor.
I think they just made a release without it (for EU or stuff) and either forgot to turn in back on for regular releases, or it didn't because of a bug.
That panel is maybe good for 200W, laying flat like this at most 120W. Continuous driving on that thing might be 5-10km/h (5mph) while the sun's high up
Obviously you go and change the key instead?