A380 requires 'super heavy' spacing between planes AFIAK, as opposed to 'heavy' for 747 and below.

Surely all the gain you get from more passengers is lost as you need significantly more spacing between the plane and the next one? So you might as well just run two 787s instead and extract more point to point incremental revenue?

Please do reply, I've wondered this for a while and haven't been able to have a good answer.