Now you've got ME confused too jackiedada !
Apologies if I've misunderstood your post but ....... the 'point' of an E or S class over a C class is surely quite simple : they are larger, so greater luggage capacity ( and more spacious for pax of course)
As for the separate issue of 'black on black' - agree, this has a bit of a gloomy feel, but it certainly makes sense from a practical perspective, given the amount of heavy use these cars get. I chose a very light coloured leather interior for my own car, and although overall I'm still glad I did, you only to have sit in the seats wearing blue jeans for a couple of hours or so before marks appear. They normally clean off without too much effort - but a bit annoying all the same.