I am starting to think drivers do not notice us with general lighting and reflectors with all the other lights of cars and everything else around.
I think you nailed it. I was in the car with my wife driving and we came across a jogger with a reflective vest and a head lamp. I saw him right away. My wife saw the light but wasn't able to distinguish it from the oncoming cars farther up the road and only realized it was a jogger once we got about 100 feet away.
A blinking light may have helped in this case, but it's no guarantee that drivers will see you.
I'm glad you were able to stop in time to avoid a collision