If you make a fresh piece of gold and show it to the world, you are proving that you have done some known — or at least bounded — amount of work.
In gold’s case, that work is gas, electricity, and human labor. If someone shows up with gold that cost less to produce, the price goes down.
Work for the sake of work is not valuable.
You could record video proving that you dug a hole 20 feet deep with your bare hands and then filled it up again.
That's a lot of work, but it wouldn't be valuable to anyone, except maybe as comedy.
However, should it be impossible to copy videos and the only way to do a video would be to capture the events as they happen, then perhaps your video would have value.
https://www.theguardian.com/technology/2016/nov/28/cards-aga...
Making origami pirate ships also requires a certain amount of work. That doesn’t give it value.