Cold messages to people in my field, do they work?

I sent 11 messages on a professional network and got two replies. I am in Memphis, in case local advice matters. Some people reply with short answers. How do you phrase the request?

I wrote three short lines: who I am, why them and a small ask for fifteen minutes. About one in four said yes.

I asked what they wish they had known at my stage. People enjoy answering that.