Well, the first one is correct because the home folder is routed to the site url; but you can just as well call the homepage with http://yourdomain.com/home. So “home” as uri and slug are correct as well.
Generally I agree that it isn’t often needed and does not make that sense.
But there’s one case where it does: If you change the homepage to something else, then the old URL of the new homepage won’t keep working. That’s why it’s useful to keep the route for the homepage.
But maybe it could redirect using HTTP 307, so that could be a new feature.
That’s a rare case I think. I would prefer to add a redirect 301 myself in those rare cases. We change the page location from a page location to a home page location. For me it’s similiar to change the slug. When we change the slug the old page route is not still there. I think it should be the same for the home page (alternative) url.
Maybe it’s just me but I really wouldn’t expect http://localhost/kirby/home to 404. It might be beneficial from an SEO perspective, but certainly not expected or consistent with how Kirby generally works. The easiest SEO fix is to simply not add links to /home in the first place, or am I missing something? I wouldn’t change anything here.
I don’t know about the benefits of the current way. But I can see quite a few problems with the proposed new way. And in general with the more complexity it adds to understand Kirby in the first place.