Cold messages to people in my field, do they work? - 12 months and counting

I sent 8 messages on a professional network and got two replies. I am in Pittsburgh, in case local advice matters. I worry about bothering people. How do you phrase the request?

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

Follow up with a thank-you and a short update. One of my chats led to a referral a month later.