Tasker is very powerful now, but certainly there are still many tasks Tasker can't do. Such as using ffmpeg converting a video, compressing a png image, run a python script, rotate a video, download a youtube video, etc.
It is so good that tasker can run Shell Code to use some command line tools that android supports. But the limitation is that android shell can not install other powerful command line tools if you have no root permission.
Yet, there is another app called Termux( a terminal tool ) can run many Command Line Tools , such as : FFmpeg,