Tbh Phoenix has a lot of boilerplate and some... Opinions that make the codepath slightly more complicated (often for good reason... that might not apply to all use cases) in the default project.

For example:. What exactly is the distinction between an endpoint and a router?

Endpoint == instance of phoenix webserver. Changing things in the endpoint gives you WAF-like control and you can do some early footwork here and store useful data in conn[:private] for you to use later in the modules called in your router

You can have multiple routers. I just built a thing where foo.com uses one router for the main site and *.foo.com is something else.

Point is, they are just plugs. You can put routes in an endpoint, it'll work just fine. The distinction is just a -often useful- prescriptive opinion by Phoenix. (Plug does not split between endpoints and routers)

very true, but the abstraction is pretty useful

it's useful if your project gets very large. It is a non-negligible cognitive cost when your project is very small and you are new to Elixir and Phoenix