Because fun USUALLY means comedy, which eventually means jobbing.
However, when you go over the top with seriousness, AKA The Ascension, then people just don't buy in at all either.
The New Day is a perfect chicken shit heel stable that gets the beauty of the tweener treatment because their antics are so fucking hilarious. There is not a tag team right now that can stand with them. The other tag team/stable that I CANT WAIT to see feud with New Day is Enzo & Cass. That will be the best feud in the tag division for years if they do it right
It's a shame they don't have appropriate foils though. The tag division now is like having Edge & Christian (The New Day) but no Hardyz or Dudleyz to counter. Look, I know we literally have The Dudleyz but it's basically for nostalgia, not to feud with New Day long term. Put The Usos against New Day in a long feud and I think the crowd end up turning on them. There's literally no threats to them right now.