Was demonstrated quite a long time ago, but is not really practical to get meaningful quantities out of it.
(That is why I always prefered physics over chemistry - my chemistry book in school started with the story of the alchimists and concluded that they were bound to fail as gold cannot be created.
And in my physics book was just the formula to create gold)
The place where this happens is in the liquid mercury target of the Spallation Neutron Source at Oak Ridge. Here, high energy protons shatter (spall) mercury nuclei, producing fragments that can include gold. An uncommon isotope of mercury can also be converted to gold by neutron capture.
you can build the entire neutron spallation reactor out of materials much cheaper than gold, and you can get unlimited quantities; the only impracticality is that the humans are still really bad at building machinery
It is quite practical. You just pour a big pile of hydrogen out, let gravity compress it until it starts fusing. Initially it will only create helium but near the end of the pile’s life you will get mountains of the other elements too.
Easy breasy. It just takes time and quite a bit of space and hydrogen. Much harder to scale it down of course. But think big and aim for a star as they say.
https://en.wikipedia.org/wiki/Nucleosynthesis#History_of_nuc...
Fusion, as you say, produces quantities that diminish very quickly for the elements beyond iron (iron 56 has the greatest binding energy of any nucleus and the binding energy decreases slowly after it), so that the last element that is produced in non-negligible quantities by fusion is likely to be germanium.