In my experience, I'm best served by trying to reinforce awareness rather than relying on it. If I got into the habit of always using blinkers regardless of my surroundings I would end up paying less attention while driving.

I rode motorcycles for years and got very much into the habit of assuming that no one on the road actually knows I'm there, whether I'm on an old parallel twin or driving a 20' long truck. I need that for us while driving and using blinkers or my brights as motivation for paying attention works to keep me focused on the road.

Signaling my turns is zero cost with regards to that action. At least for me, signaling as a matter of habit comes at the cost of focus.