When you install Ubuntu, it obviously has to install default drivers to work, such as internet drivers and video card drivers, but which drivers does it install as well?
I know that it will look for a very limited spectrum of semi-third-party drivers such as controls for video cards, but as we have all seen, not all drivers are installed by default. Is there a certain list of non-essential drivers that Ubuntu will install by default?
The number of drivers are in the thousands I imagine. Your list needs to be expanded to include drivers for USB, wifi, ethernet, bluetooth, mouse, keyboard, touchpad, laptop ACPI's (like my Dell and Toshiba you probably don't have), CPU's, GPU's, etc. Some drivers like Nvidia GPU are optional and appear on Ubuntu's "Additional Driver's" tab under "Software & Updates" in the "System Settings" menu.
The majority of drivers don't come from Ubuntu but rather the Linux Kernel. New Kernel version can add more drivers for new hardware.
Do a search on *.ko files to get an appreciation of the scope of your question. I wouldn't want to take the time to go through and decide which ones are non-essential.
If today you don't have an Intel WiFi card would you want to delete the drivers as "non-essential" only to have a new Intel wifi card you install not work in the future? Besides after the next Ubuntu kernel update, all the "non-essential" drivers you deleted are installed again plus new "non-essential" drivers.