Suicide Squad Reviews: 10 Things We Learned About The Joker
7. Remove Him, And Nothing Changes
He might be all over the marketing materials, but it seems the Joker isn't actually in the film all that much. The best estimation seems to be around 25 minutes of screentime (though that's not too bad considering he's a sideshow).
What is slightly more concerning is the fact that he doesn't seem to be all that relevant to the plot, as Variety put it, he's "grafted on". According to US Magazine's review he "slips in and out of the movie with barely more than a menacing smile" but his "extended cameo may come as a disappointment" because "Ayer couldn’t figure out a way to beef up the part."
The FilmFile says "Ayer's screenplay wastes Leto to such an outrageous degree it almost feels like a cruel joke," and it seems to be a shared sentiment.