It's probably a symptom of the ridiculous defense bonuses and dmg/lb penalties. When people can't have much impact alone, they are vastly more likely to group up.

Frontlines relies currently way too much on people deathballing together, which vastly increases the value of coordination and picking Jobs with absurd AoE potential. You can't even have proper 1v1 when half of the Jobs take barely any damage in such setting.

I'd rather we go back to incredibly explosive Bahamut swarms and other stupid stuff than have this current meme meta. At least with that you can pretty aggressively split up and contest multiple things on map instead of relying on having a blob of people to kill a single Ninja.