Implementing Amazon EC2 Auto Scaling will allow the company to adjust the number of EC2 instances automatically in response to changes in traffic, thus ensuring steady and predictable performance. By scaling the capacity up or down based on demand, the company can maintain performance levels without over-provisioning resources, which helps to minimize costs. A Load Balancer would distribute traffic but not handle the scaling of compute resources. EC2 Reserved Instances provide cost savings for consistent usage but do not auto-scale, and AWS Lambda is serverless and used for event-driven workloads, which may not be suitable for a traditional web application architecture.