Think of all of the random conditionals that your http routes have; "is the client posting a correct data structure" or "is this a valid OAuth token" or "am I requesting something that I already have cached" or rate limiting or the list goes on and on.
All of that kind of stateless route level logic that may not need to hit a data store is a perfect candidate for an edge worker, because once you have that deployed, you can concentrate more on business logic within your main application.
For example: "I have a valid OAuth token, I have established my identity, now issue an S3 pre-sign request and forward the resulting URL to the browser to download a protected file". Doing that within a worker will absolutely speed up your user experience by a couple hundred milliseconds at least.