Honestly WoW does it pretty ok, but there are definitely issues with scaling in the sense that lower level characters do considerably more dps than higher level characters in a dungeon as well as scaling of different expansion's dungeons can by wonky at times. I think if they dedicated a team to do a balancing pass on leveling dungeons it would be in a really good spot.
That being said, FFXIV and WoW have different mentalities when it comes to dungeons. Instead of syncing characters in dungeons they sync mobs to your characters level. I think that is a massive difference in mentality towards the issue and honestly makes it very difficult to compare the two.