Cold messages to people in my field, do they work? after 15 years as a social media manager

I sent 15 messages on a professional network and got two replies. It has been weighing on me all week. Some people reply with short answers.

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.