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.

> > I don't understand how none of the alternatives really embrace WinterTC

> You provide handlers that fulfil requests from the system.

As I said previously, though I wish they were, such handlers are not part of WinterTC.

And then again, how those handlers are registered is also not part of WinterTC, which I also wish it were.

> APIs like that leak implementation details

How?

Almost all runtimes, like Bunny Edge Scripting, Cloudflare Workers, Deno, Bun, etc. use the same basic signature for the handler:

(request: Request) => Promise<Response>

Only how you register said handler is, unfortunately, different for each runtime.