What is the purpose of a warm call?

I typically connect with clients via email, and those who show interest tend to respond. Once they do reply, I’m unsure of the next steps I should take. I usually hop on a call to discuss the job details and bring up my fees. I’ve learned that the goal is to identify their pain points and demonstrate how I can address them. However, I’ve noticed that even when clients express interest, they often don’t follow through, and getting them to sign a contract feels nearly impossible. I understand that this is a numbers game, but why would someone take the time to speak with a recruiter, mention that they work with agencies and need assistance, and express satisfaction with the fees, yet not sign when the contract is sent?

I feel like I might be missing something in this process, and I would greatly appreciate any insights or advice.