Steam not working on Ubuntu 20.04

This worked for me.

sudo apt-get install libnvidia-gl-440:i386

This worked because the issue was with the graphics and Ubuntu 20.04 combined. This library has 32bit files for Nvidia's gpu. These 32bit files were removed while upgrading from 18.04 to 20.04.

Though they asked about it, on which most people just clicked on ok continue. I did the same.

Edit: as of 26, July 2020, nvidia's driver 450 is available but it's i386 is having issues. So until then stick with 440.