I personally think its a very bad idea. “He treats his wife so much better” “She is more attractive” “He makes more money” “She makes more money” “They already have kids and they are so cute” “Why can they afford a 3 bedroom and we cant” etc. Its probably a great way to ruin your shabbos and get into fights unless you are clearly the couple society places a higher value on. Very often, the other couple is at the “top of their game” so the visiting couple or host do not even see what goes on behind the scenes.
But on the other hand people have a way of making friends with others who have the same type of income and status. If you dont, often you will not be invited in the first place. I still think the couple should have meals either at their own place, family or go to middle aged to elderly couples.
Its interesting why the question was not asked about older couples- I guess because couples in their 60s don’t care about these things anymore.