Why not both? What do you see wrong with having gpt spit out a complicated ffmpeg filter chain and explaining every step of the output, which you can then look up in the docs and unit test before implementing? I find verifying the gpt output is still quicker than consulting giant wall of text man pages
Fish and learning to fish. The latter widens your perspective and give you more options, especially if there are a lot of rivers nearby!
You are saying one should learn to fish with a spear not a fishing rod
Virsh has a --help screen that shows a command listing that is 20000 characters long. I too would be intimidated.