Why do girls just stop talking?

I'm not referring to dating but an example, a girl who used to hit on me and I didn't respond because she was ditzy. We did a sport together for quite some time. Anyways I messaged her several years later to inquire about something she's familiar with and she asks how I have been n all. I reply with a few questions and she doesn't respond back? I've had two other acquaintances that were the same way one male one female. So why do they even bother asking questions or in some cases reach out then just act like they want nothing to do with you? Are people just that bad at communication? Or understanding social interactions? I feel like they live life as a tik tok clip. It's very annoying.
Why do girls just stop talking?
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