Wow, that's a massive blind spot you've got there.

The value comes from doing the thing. Fixing the tractor creates value. Growing and harvesting the potatoes creates value.

Trading the potatoes for something you value more, yes, also creates additional value. But notice that potatoes have value to you even if you don't trade them for anything.

If you choke on a grape and a helpful volunteer saves your life, they create value. Nothing was exchanged, but they sure as hell generated wealth right there.

Labour and voluntary trade both create value. I wonder what sort of mindset one must have to forget that labour exists.