The fight has changed, but when
i always laugh when people label exp dungeons as "hard"
You're such a helpful and valuable member of the community.
The encounter was changed with the last patch to make it harder, but as others have said, when done a certain way it's not that bad.
If your party can't manage to take out two or three silver mobs with about five of the hatchlings, you're going to have a hard time. Personally I don't think it's that hard and when I see people struggling with the spiders, it's because they aren't focusing them down and for some reason approaching the adds differently from how you would any other encounter.
You used to have to clear the first few mobs in front of the tree and from then on you could AFK it. The recent patch caused more spiders to spawn and attack you in the tunnel regardless of what you do. There is also the tree bomb skill. There is one bomb for each ally, if you all stand in the same place you are all hit by each other's bombs. This causes everyone to be downed, so spread out and dodge roll when you see the tree slam its fist down and start to shake.
Just stand at max range like before and kill the spider adds as they come to you. If your party is decent they should be able to DPS the spider adds without leaving the room and letting the tree reset. If your party struggles, you will constantly reset the tree, however there does seem to be a cap on the number of spider adds he sends after you so even if you reset him multiple times, eventually you will kill all the add spawns and can essentially auto-attack him and only have to worry about the egg skill. I read that if five people are hit by the egg bomb skill he will throw spiders at you. I've seen my whole party downed by that skill and no spiders spawned, so I don't know how true it is, but there is incentive to dodge the egg sacks.
Don't let the spiders overwhelm you, focus them down and use AoE to take care of the hatchlings. If your party can't handle a few hatchlings and three silver spiders, you need to work more on your skills because it shouldn't be that hard.