You don’t understand.
The inputs from those areas have been declining in producing things not that the economy has declined because they are less and less of the economy.
We are using less and less of these inputs for many reasons. The most striking is the gradual de-materializing of a product. How many trees did it cost to produce a book vs the ebook? How much labor goes into making a watch when there is a phone that tells you the time. The computer itself has been reduced from machines which fill a room to one weighing a pound or so and which can do millions of things more.
We are exporting raw materials and importing finished goods like a third world country. Hence HUGE trade deficits. It’s embarrassing.
Free Traitors™ peddle economic terrorism. Snake oil.