These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Creative Sterility: Oda eventually seems to reach the reasoning that the Drifters are bringers of new technology, and new knowledge, and seems surprised that people in that world overlooks the potential of their inventions.
It's not just the people of that world either. Some of the Drifters who have been around for a long time like Abe no Seimei don't realize the potential of what they create and use in that world, which is also mentioned by Oda.