Overclocking
Is the process of increasing the clock rate of a device, surpassing the intended speed set by the manufacturer. The whole purpose of overclocking is to increase the overall performance. (Note: Extreme overclocking can cause system instability and overheat.)
Customization
Android phones are already impressive when it comes to customization, but customization with root is on a whole other level. You can tweak every aspect of the OS, including colours, shape and system files.
Battery life
Can be improved by flashing a better-optimized kernel or a more efficient operating system. You can also use some of the root apps that focus on tweaking battery files to improve battery life.
Flash custom ROM
Most custom ROMs tend to have more features than the stock ROM that comes with the phone. Another advantage of custom ROMS is the ability to use newer versions of Android on older phones. (Note: Custom ROMS should only be downloaded from reputable sources)
Removal of pre-installed OEM apps
You can easily free up space and improve performance by uninstalling bloatware and system apps when you have root access.
Ad-Blocking
Almost every free app has ads now. Understandably that’s how developers make money. With root, you can block ads system-wide.
Flash Custom Kernel
A kernel is the core program that manages your phone’s RAM, CPU resources, system memory, and hardware components. With root, a better-optimized kernel can be flashed to improve battery life, connectivity, performance and add new features.
Underclocking
Is the process of decreasing a device’s clock rate to reduce power consumption, heat emission and improve battery life. I once owned a Motorola Atrix that kept overheating. I had to root it and underclock the processor to fix the heating issues.
Breath new life to old phones
Most smartphone companies don’t release the latest Android operating system or security updates for their old devices, leaving them vulnerable to malware. With rooting, you can easily flash a custom ROM of the latest Android OS, improving security, battery life and performance.
Root access
You’ll have access to the core files of a device. It’s always advised not to mess with these if you don’t know what you’re doing.
Display options
You change the resolution, orientation and DPI settings.
Backups
With root, the whole OS can be backed up and restored without losing anything, including app files. Apps can also be backed-up using Titanium Backup which leaves no stone unturned. When you restore the app, it would seem like you never closed it.
Dual Booting
Yes, with root access you can flash two separate operating systems on your phone. Why would anyone do this? I’ll let you answer that.
Power Apps
There are a lot of apps that are not accessible without root. Some of these apps tweak system files to add new features and improve performance. An example could be an app that could use your phone to extend your home’s wifi. (Samsung’s latest phones already do this, but there was a time you needed root for this sort of feature)
Change boot animations
Have you ever gotten tired of seeing the same animation when you turn on your phone? With root, you can easily replace it with a picture, video, message, logo or whatever you like.
Anything is possible
If there is a feature missing in your smartphone, rest assured it can be achieved with root. This statement is less relevant today, as phone manufacturers provide a software experience that is robust enough, with features that people used to root smartphones for. Some of these features include multitasking, themes and heavy customization.