Handicap system for new players at end game?
After running some encounters at end game and seeing how newer players are getting treated simply because their learning experience leads to the deaths of those who are more experienced, I think it makes sense to have some kind of handicap system in place that gives the newer players a buff based on some kind of metric relative to the more experienced players. So if a new player joins a Titan hardmode group that is "farming" Titan, that player would get a buff since the farm group members likely have more Titan kills than the new player in question.
I mean, it's an idea at least. We already have people being forced to sneak into these runs in party finder (not saying that is a good thing), at least this would help ease the burden on the rest of the group hypothetically.