Why are modern caravans so heavy?

I recently went to the Milton keynes caravan show and had a general interest look around what was on offer.  In order to get a newer caravan with the same space as my current one I would have to upgrade my tow vehicle too.  My current Caravan, a 1989 Lunar Arianne 6 berth has a shipping weight of 15.75cwt and loaded max of 18.75cwt (approx 800kg and 950kg).  the 'van has served me well since I bought it in 1996.  Is it just that the manufacturers insist on us having all the latest gadgets and luxuries or is it nanny state insisting on all sorts of protection for the hard of thinking?  For now I won't even consider trading in there isn't a caravan on the market that would better suit my needs!