Bandwidth limiting is sometimes done in an application but it depends on what you’re trying to accomplish by the limiting and what protocols and resource types are served.
If you want to keep track of how many bytes have been transferred for each site you serve, and then stop serving a site after it reaches a monthly quota, you are better off doing that in a load balancer or reverse proxy. A comparable WordPress plugin would be overly complex to produce and costly to use due to added inefficiencies.