Artificially Increase Maximum Screen Brightness

Run this to see a list of your outputs. You're looking for the one that is "connected":

xrandr --current

Here's a screenshot of my list. The output I want is the "connected" eDP1 at the top:

Now you can run these commands to make adjustments. Replace eDP1 with the name of your output, and change 1.2 to make the adjustments:

xrandr --output eDP1 --brightness 1.2
# Note: 1 is default

You can also use gamma instead of brightness:

xrandr --output <outputname> --gamma 0.5:1.0:1.0
# Note: 1.0:1.0:1.0 is default