Channel index page linked in a structure I come from expression engine and what I want to do is the following: I have a channel filled with entries. All I want to do is to list all these entries on a page.
However, I don't want to link through to a detail page. So I disable the "Entries have their own URL's".

Now I can link to this channel by linking to its handle in my url.

Problem now is that I use a structure to build up my navigation. And you can't link to a channel in a structure, only to its entries. So I need to create a (useless) extra single section to link to and list all entries from my channel in that single.
Shouldn't it be simpler than that?

I didn't find a better way to handle navigations yet.
The reason why there's no automatically set url and template for channel index pages is because Craft tries to be as flexible as possible. In many use cases for channel sections you don't want a index page at all or you could also need multiple of them.

But you already chose a very solid approach by setting up a structure section for your navigation. And no, you don't have to create useless singles for each channel index. I'd rather use entries of that structure itself and would just set up a new entry type for your indexes. See this article in the Craft Docs on how to link templates to entry types.

I think it's really nice to have all the site main pages together in one structure. You can easily add fields to your index pages and have your client edit all this rather static content in here.

You can also add you home page to that structure. See this Q/A for how to do that.