The game is heavily skewed to benefit groups more & more the higher you go up in the map tiers. Even before OBT, in closed, it took significantly longer for me to solo or duo a high level Map. But our guild could roll in there as a full party and chain clear like 12 68 Maps in under an hour.
Natch, I could faceroll low level Maps solo.
Think the party/no party disparity in the higher Maps could be better balanced. Or at least smoother. The highest level Maps are just too party skewed.