Creating a conference line with Twilio Functions allows for easy and seamless joining of calls without the need for additional setup or configuration. A Twilio account is required to create a new Function, which can be configured to handle incoming calls by generating TwiML that tells Twilio to dial the caller into a conference room. With the basic code in place, users can then buy a Twilio number and configure it to call their function whenever someone calls the number, allowing for the creation of a fully functional conference line.