Yes, I agree that delivery folks can be particularly dangerous. I also watch out for ridershare drivers as they are frequently distracted by their phone and in a rush.

The small size was a major problem here. I probably would have seen the scooter rider earlier if they were a driver running the red light. I now always check for red light runners at that intersection.

(As for how visible I was, I was wearing a hi-viz jacket at the time. My air horn seems to have been the only thing that caught the scooter guy's attention. Not sure what more I could do.)