During the American revolution, we rejected the idea that people should have titles. We like job descriptions and think people who use honorifics are putting on airs.
I wouldn't call someone with a master's degree "master", so I'm not about to call someone with a doctor's degree "doctor".
"only people of the medical profession correctly use the title of doctor socially" —Miss Manners
My take: The only people who should be called Doctor in social settings are musicians, superheroes, and supervillains.
After doing a little research on titles in the US, I'm both creeped out and not surprised that as the wealth gap grows, it's becoming more common for PhDs and JDs to be called Doctor in social situations.