Why Game of Life automata always ends with Still life?

Hello everyone, I've been playing with Conway's Game of Life[1] lately and I noticed that most of the times when generating random grids in a terminal emulator or web apps almost always the output[2] ends with Still life and Gliders. Is there a mathematical reason why this scenario happens and why Gliders are more prone to be generated?

[1] https://copy.sh/life/

[2] https://i.imgur.com/CLMjFxe.png