NVIDIA display issue with brightness control and video playback

Solution 1:

This solution was initially posted by the OP as a part of the question.

To remove the NVIDIA drivers completely

sudo apt purge ^nvidia

Some of the additional components which may raise issue need to be removed

sudo apt purge bumblebee vdpauinfo vulkan-utils 

The removed and the pending dependencies can be fixed by installing the Ubuntu Desktop

sudo apt install ubuntu-desktop

In some versions of Ubuntu the xorg config will create some issue so it needs to be removed. If not found it will be well and good.

sudo rm /etc/X11/xorg.conf

Now make nouveau the default driver

echo 'nouveau' | sudo tee -a /etc/modules

If nouveau was blacklisted it is advisable to remove the blacklist

sudo rm /etc/modprobe.d/blacklist-nouveau.conf

This the last and the final step of the process

sudo update-initramfs -k all -u

Reboot the computer and check the brightness controls and the video playback.