#2 Not enough quality opponents

Some of the best things The Shield had going for them in late 2012 through 2014 were the amazing six-man matches we got to see. They defeated a wide variety of teams consisting of talents like Ryback, John Cena, Kane, Daniel Bryan, The Undertaker, Randy Orton, The Big Show, The Usos and CM Punk.
In their match with The Wyatt Family at Elimination Chamber 2014, the crowd chanted “This is Awesome” before the match begun. It was a golden era of high quality six-man tag matches and The Shield had a lot of wonderful talent to feud with.
That is simply not the case in 2017. It certainly doesn’t help that the brand extension limits the amount of heels for The Shield to fight in 2017. I don’t think a lot of people where excited to see encounters with the likes of Bo Dallas and Curtis Axel.
Sheamus and Cesaro are great but they literally ran that possible feud into the ground with too many matches in a short span. The best match by far was with The New Day but the brand extension limited the possible chance for a rematch.
The WWE had a lack of strong heels and The Shield floundered because of it.