It's fine, just uses a couple of watts probably to do so.

I always turn my monitors off but there isn't really any harm in keeping them on.

if you are unlucky and there is power surge like lighting strike, could damage it, true story

you can set windows power settings to turn off the display
and/or use screensaver

or winkey + L to quickly log off

or make a shortcut to .scr file and assign that to like alt+f12 or something

or in power settings, you can change power button to sleep or shutdown

its fine either way you do it.

have a nice day

in every manual I seen there is a tech sheet at the end where it states power consumption in standby or off

if theres a lightning strike it dont matter wheter its on or off.. if thats likely you need surge protection