A URL is beautiful conceptually. It points to an entity, is easy to remember, and often speaks conceptually about what you might expect to find at that entity. Hence, it translates written language into an addressable point on Earth, allowing you to easily remember thousands of them, and such access the point behind the URL. It allows you to move the point implementing the URL around as you see fit, and exchange its inner details, without having to change the URL. Pure brilliance if I may say so!
A function on the other hand, has arcane syntax, often contains weird looking characters, and due to its arcane syntax, seldom allows you to remember more than a handful of them. In addition, the lack of a “function DNS system”, prevents you from easily traversing meta information behind your functions, and such increases the cognitive requirements to remember what they do.
So why don’t we treat functions as URLs?
Well, actually you can.