Power Saving Blank Screen

I was using xscreensaver til now but it isnt the most reliable.
If I use the “Blank Screen” option in power saving I have to log in when waking,
will all background tasks still be running while the screen is blank?

I need to keep my laptop on all night and stay connected to wifi while screen is off

You can set to have the display turn off after some time, without putting the system to sleep or hibernate, so in that case all the tasks and applications will still be running.

Can it be done using any keyboard shortcut? I also wish if there were any way to turn off the screen alone with system running. In mint I could turn screen off by setting brightness to minimum

One way to do it would be using ‘Super’ + ‘L’ shortcut. This is used for lock screen but gives the same functionality. I was able to play video in browser in lock screen (audio only) with screen blanked. So I think it functions similar to blank screen with programs running in background.

I use this now and I suppose it should suffice your need