Maybe you weren't around when a Required Hand Gesture for braking, turning, slowing, and stopping was the norm. Then only after years of progress, style, and government intrusion did turn signals and brake lights finally relieve the driver of that required hand gesture to signal intent. Further, brake lights, turn signals and hand gestures can be ignored.
Brakes on the other hand are a fact of engineering and a requirement to operate the vehicle. Stopping distance is what's regulated.
I made the required hand gesture to the idiot who pulled out in front of me this morning - does that count?
Large trucks use the engine for braking when stopping distance is the issue.
As for handsignals and such....a better way has evoloved. One that does not require distraction on the part of the driver, those being automatic lights. This came about partly because of increased traffic and the need to remove unneeded tasks to perform.
You may call it a removal of intent but then you are just being obtuse about it. Signaling with a hand gesture is the same intent as signaling with a blinker. Simply a different tool used to do so.
Your last paragraph hold some merit. Seat belts aplly to what you said just the same. That was my solution to much of the opposition now wasn't it? Engineer the use of seat belts for operation just as the brakes are.
One could even argue that a seat belt is about stoppng distance also. In relation to your seat and the windsheild that is.