Consider the incentives of the people at the FAA. Their incentive is to never approve a design, because if they approve a faulty design, they get the heat, too. It's much safer to just not approve anything, or at least delay demanding ever more documentation.
Hence there's always going to be a tug of war between the FAA and the industry. The FAA never wants to approve anything, and industry goes out of business if the FAA doesn't approve it.
You'll see the same forces in action with the FDA.
BTW, as is abundantly clear from history, a fatal design mistake can and has destroyed several airframe companies. Boeing's finances were punished severely after the MAX crashes. Boeing does not win by making an unsafe design. When I worked at Boeing, I didn't know any engineer who was willing to sign his name to a faulty design. Yes, the engineer responsible for a piece of work gets his name on the drawings. It's career suicide for him if he signed off on a bad design.
Hence there's always going to be a tug of war between the FAA and the industry. The FAA never wants to approve anything, and industry goes out of business if the FAA doesn't approve it.
You'll see the same forces in action with the FDA.
BTW, as is abundantly clear from history, a fatal design mistake can and has destroyed several airframe companies. Boeing's finances were punished severely after the MAX crashes. Boeing does not win by making an unsafe design. When I worked at Boeing, I didn't know any engineer who was willing to sign his name to a faulty design. Yes, the engineer responsible for a piece of work gets his name on the drawings. It's career suicide for him if he signed off on a bad design.