When I was younger, adults used to answer the phone with "Hello, this is MyName, who am I speaking with?"

Pragmatically, even basic words from your voice can be used to estimate your age, gender, and geographic region (local accents).

But also read other comments, people are saying they answer their phone by stating their name, so plenty clearly use it as a greeting.

I think the op was maybe on a bit of a tear and misspoke, but the sentiment is correct. These days even saying hello can be used to make a decent voice clone with some reasonable (say 50%) chance that it is you (your phone number is linked to a ton of information). I would personally try to minimize my exposure to this risk even if it is somewhat paranoid.