When you’re grouped with players your same level you should but what most players are griping about in this thread is when we could power level by having a high level player running players through dungeons that was allowed for 14 years but stopped in patch 7.3.5; I did have a CM tell me on another thread that the Devs could not figure out how to stop this until the 7.3.5 patch.
And the leveling speed while questing in certain zones especially like WoD’s NPC’s that have some in areas that are nearly impossible to defeat.
Also the amount of stats our heirloom gear has now vs regular gear and azurite gear as the below post explains.