Doing EW leveling dungeons again, and I have to say, the damage output that occurs on those dungeons compared to max level or "Expert" dungeons is far better. To be fair, this is likely because the player doesn't have their entire Job kit yet and some players are under leveled in terms of gear, but there is a difference. And if I have to be honest, I am playing a BRD at the time and the healer (who was an AST) still spammed one button most of the time, but seeing him stop for a second or two and use more of his kit in mob pulls (and the bosses too to some extent) was refreshing to see.

"Expert" dungeons don't have a lot of incoming damage. There maybe some exceptions, but due to a lot of factors like gear and having your full kit, incoming damage just doesn't hit as hard. And don't get me started on the dungeon bosses. For God's sake, I have not seen a max level dungeon boss hit hard since "The Burn" back in Stormblood.