Game may have a memory of your struggles and challenges on its own. There was a theory of encountering specific monsters or elite abilities more frequently usually rely on your previous deaths, or what recently activated your cheat death. There could be a mechanic where game simply toss the same challenge at your path until you learn how to defeat them. It may have record your previous encounters and recall which one gave you a tough time rather than giving you a random encounter that you can trash and lose interest.
I remember threads about this theory and it suggesting you to die to other elite abilities repeatedly in Softcore, if you want to avoid such roadblocks. Because back then, classic D3 was more brutal compared to what it is today. Perhaps it had some weight on the system of the past, but it could all be all about our selective perception from the start as well. In general, game has to mind the usual flow and try to give you challenging encounters in between easy ones so it can catch you off-guard whenever you try auto-pilot it.
When you learn how to fight certain encounters by exploiting crowd control, when to do sharp maneuvers or delay your buffs by anticipating attacks and so on, these would stop being a challenge. At the same time, they will not block your way as often as they used to do.