What are 3 disadvantages of a WAN?

Can you elaborate on some of the drawbacks associated with a Wide Area Network (WAN)? I'm particularly interested in understanding three major disadvantages. Firstly, how does the geographical span of a WAN potentially lead to increased latency and reduced network performance? Secondly, what are the security challenges that arise due to the extended reach of a WAN, and how might these affect data privacy and confidentiality? Lastly, could you discuss the financial implications of maintaining and scaling a WAN, especially in terms of the costs associated with hardware, software, and ongoing management?