Why don't cyclists wear riding gear like motorcyclists?

As a motorcyclist exploring cycling for fitness, I've noticed a lack of protective gear for cyclists. After some research, I found that people attribute this to factors like speed, freedom of movement, and weight.

However, with recent advancements, armor has become light, flexible and thin enough to not restrict movement. Regarding speed, I've seen cyclists on highways traveling at speeds I consider unsafe, with a significant risk of being hit by a car.

I recently read about a surgeon who became paralyzed due to a spinal cord injury from a cycling accident. Can anyone explain why cyclists don't wear riding gear like motorcyclists?

Update: My question is more about why specialized protective gear hasn't been developed for cyclists.