Grouping Advantages?
2 reasons:
-“Anti-dc”. Usually used in maps that are more likely to be full. In essence it means that if you disconnect, you’ll be more able to taxi back in to the map shard you were in, as you have a party member in there already. It also means that in non-hard-cap maps, you’ll be placed in the map shard with your party members, rather than a fresh one (which might mean you don’t have to wait for pre events to be completed again, etc).
-The second advantage is that if you don’t deal much damage to the boss, you’re more likely to still get credit for the event if you have party members who are also dealing damage to the boss. If people are doing champ trains or farming zergs in WvW, you’ll get more loot this way as you just have to tag a foe in order to get the loot.