It’s time to increase respawn timers for all normal mobs (not named) in the entire game. It literally is a 30 second timer from when you kill them to when they come back alive, and re-aggro you. It was understandable at the start of the game when there were so many players, but the quick respawn is absolutely not necessary now.
Trying to kill a named target for a quest that’s elite for example, we shouldn’t have to kill 3-4 other mobs that constantly respawn, while also trying to take the elite enemy down. It makes it nearly impossible in some cases to complete these quests unless you can find others in the area, which isn’t always easy or possible, especially on “medium” to “low” pop servers.