It really depends on the situation and the game that we are playing...6v6 crucible world probably net the IB guys more wins but a 6v6 raid world net faster clear times by the raid guys. Generalizing that Raid guys are horrible pvp players isn't always true just like pvp players aren't horrible pve players. I choose not to play crucible bc it's not what I enjoy but have a positive k/d in control and have a better than positive k/d when I choose to play IB but prefer pve content. I stand in the middle on this subject. It takes no more skill to grind IB than it does to do raids for gear. I do think if RNG is unkind to you it can take longer to get raid gear versus IB gear but doesn't take any more skill