Good stuff. I've never called a stranger "sweetie." It has always seemed. well, like you describe it.
Somewhat related: I was in the hospital for a week. When two cardiologists came into my room to chat with me about how to avoid impending death, I found myself more engaged with the male doctor even though I was much more interested in what the female had to say. Why is this iso? She's the one I'm going to call for aftercare questions, not the guy. But then I realized that he sort of wanted the room, and I let him have it. I switched gears and stopped latching my eyes oto his and looked at her instead of him while he talked. But it's an interesting dynamic that your headline made me think of . Specifically, the word "subtle." This wasn't an older woman thing. She is very young. But it caught my attention even as it was happening.
That's not misogyny. I think women are amazing. But wow, it's just incredible how pervasive subtle discrimination can be. We all seem to think it's okay to be dismissive towards women of all ages. I can imagine how this feels worse with age. I think if I had a phrase to refer you with, rather than "sweetie," I'd say "Oh wise one!" :-)