OpenGL allows you to build interesting things like filters and effects on videos, or some interesting mathematical patterns that produce beautiful wallpapers. These two examples below, just touch the surface of what OpenGL can do: Example of what you can build with OpenGL Another example of OpenGL usage – OpenGL ES is a cross-platform graphics API that specifies a standard software interface for 3D graphics processing hardware.
In 2018, I started my journey of learning OpenGL, we were migrating our app from using the Android Canvas system to using the more flexible (but indeed more complex) OpenGL ES.