This has been a problem for a long time, because 8-person and 24-person content is not item level synced. This means that by the end of the expansion, we have gained more than
100 item levels over the earliest content of that expansion. The result is that content from the first 2 tiers have raid-wide AoEs that feel like they do 2% damage, you can stand in everything or skip all the mechanics; almost nothing matters. The content is a striking dummy.
To get a sense of how powerful a difference item level can make, even just an increase of 5 item levels to each party member significantly warps how the content feels and can make a lot of mechanics not matter as much, ease up DPS checks, and reduce the need for mitigation.
Even within the same raid tier, if all the party members are max item level (just 20 item levels over the crafted gear item level), they can destroy the earliest savage floors in about half the time. Yes, I said they can kill savage bosses half way through the fight!
Now, you may wonder what happens when the content is old and we level sync. There is an invisible item level associated with that level, which is the max item level of the expansion. Here is a list, which I never forget:
- 90: 660
- 80: 530
- 70: 400
- 60: 270
- 50: 130
So to answer your question, the first Pandaemonium fight is scaled for item level 565, while players are synced down to 660. Think about that for a moment.
All 8 players are probably 105 higher in item level.
Over time, this problem gets worse due to battle system changes. Older fights from, say, Heavensward, have gone through: Stat changes (Parry becoming a partial DPS stat, Accuracy becoming a proper DPS stat, multiple Determination buffs, a Tenacity buff), the removal of stat assignment, a rebalancing of gear stats and tank damage, regular potency increases for years to compete with how overpowered new jobs are because they are afraid of nerfs, a stat squish (which actually made Heavensward content last a little longer, this was a slight improvement), lower level rotations being made hard to mess up so you can do everything easier than you could back then.
Will they do anything about it?
Probably not. We've been asking this to them for years. It's been brought up to them in interviews and Q&As and they agree... yet they do nothing about it. But maybe someday they will randomly address it. Like they do with all Quality of Life - they address things that have been an issue for 10 years at complete random.