2) There’s A Noticeable Lack Of Depth
Hardcore cinephiles would probably argue otherwise, but comic book movies can be deeply emotional and thematically rich pieces of work. Marvel certainly endeavors to make its films more than just set-pieces and the occasional catchphrase – just look at something like Thor or The Winter Soldier, movies which ponder toxic familial dynamics and the threat of government over-surveillance in a post-Snowden world, respectively.
While Marvel’s movies are entertainment that generally try and make a point about life or the wider world, Deadpool isn’t burdened by such intentions. The film is, rather, too busy having fun to ask itself questions regarding mankind and the state of things.
It doesn’t make the movie any less enjoyable, but Deadpool is absolutely less concerned about making you feel or think. The MCU has the edge in that it might actually leave you talking after the screening.