alt Hacker NewsAFAIC, WinterTC doesn't specify how to start an HTTP server. Their minimum common API requires, among other things, that the Request and Response interfaces from the fetch specification are present. Unfortunately, it does not specify any sort of serve function.
Because an edge runtime should not directly start servers in the first place. You provide handlers that fulfil requests from the system. Edge runtimes that pretend to start the servers in the edge worker context are flawed and ugly from the very start. APIs like that leak implementation details and increase vendor lock-in for no added benefit.