Why don't I need to install any Drivers for Ubuntu

For the most part, you don't need to install additional drivers. Almost all available drivers are included.

Ubuntu comes with many drivers out-of-the-box. You may need to install drivers only if some of your hardware is not working properly or not being detected. Some drivers for graphic cards and wireless adapters can be downloaded.

The easy way to find out if any drivers are needed is to choose to Try Ubuntu from the installation screen first to see if you need any drivers and to see if Ubuntu is working with your hardware.