My experience with the FDA:
I'm "congenitally limb deficient" below the elbow. Grew up in the 90s using horrible myo electric prosthetic limbs that had 2 hour battery life and were in all practicality a glorified claw machine. I ditched that as soon as I realized they were actually a hindrance.
In 2006, there was a TED talk with Dean Kamen about a prosthetic arm developed by DARPA. It blew my mind and got me finally interested in wearing a prosthetic again. So much promise in a field that had been in a coma for the last 20 years.
That arm never happened. Why? Because it took the FDA 7 years to approve it. The project now is dead in water and the group responsible for building it is trying to literally give away their designs. Why did the FDA have to approve a prosthetic limb? Well, because it touches your skin. Yes, the silicon on the back had to be tested because of skin contact.
I'm now the lucky recipient of BeBionic 3 arm, which is great. Worst part about it? It uses radio frequency to control the hand and has a tendency to go haywire. I asked why they didn't just use Bluetooth and he said that would require another 2 years to get FAA approval. Ugh.
Anecdotal, I know.