Any content that requires a large group is only as difficult as it is to get a competent group together. Raiding isn't that hard on the individual. Once you learn the fight, and if you are accompanied by a group of people who have also learned it, it becomes easy. The perceived "difficulty" comes just from the fact that it's so easy for one person to mess up and screw everyone else over. If people actually looked for real difficulty, they'd look for solo challenges, where success or failure really depend on the individual alone, not on whether or not the rest of the group does their job right.