You got it backwards. "The Suicide Squad" is the only redeemable one of the three. The original movie was meant to be a ripoff of guardians of the galaxy but it was written poorly due to a writers strike at the time. This was made worse by the fact that they took two different cuts of the movie and stitched them together and it really shows. The second movie is just "Yas Queen" because they were unhappy they ruined casting Margot Robbie in that disaster of a movie. "The suicide squad" was directed by James Gunn who also directed GotG so it's a redemption arc for the storyline. It's like a pseudo reboot kind of like how deadpool is an reimagining from xmen origins wolverine. If we were to try to say Deadpool was a pointless movie because Ryan Reynolds was already Wade Wilson, this would completely undermine this awesome direction comic movies are going where they're infused with more comedy. GotG, Deadpool, Thor Ragnarok... these comedy driven movies are some of the highest rated superhero movies. What's pointless about having good writing instead actors talking in front of a green screen with lazer beams?