Sometimes doing a run with a gimmick can be what it needs to feel new again. Terraria has great exploration but isn't super replay-friendly on the other hand, if you've already beat the latest patch and know how to reach the final boss and get every item from where then you would practically need a special reason to play the game again otherwise it would be more of the same but in a separate save file (if you wanted anything, you know how and when to get it, it's not like you'll come across a super-boosted gun or accessory in this world that will make you feel like switching strategy or happy that you got it), unless you wanted to do a different/special run this time.
Sometimes replaying is even annoying for building stuff again because you have to do it all from scratch and there's no incentive to not just leave placeholder block houses (IMO it would be more fun if you could find special old delapidated houses different in various biome surfaces in randomized already vaguely proper shape housing 2-3 people and then you just clean them up and finish them yourself, even a place near underworld middle to make it intuitive to place the underground pylon there).
-Class runs, where you decide on a class for your character and you're only allowed to use weapons that do that type of damage. It's fun because even if you knew the world upside down, there's only certain things you can use to go forward and you HAVE to go for it.
Too bad there isn't an actual setting for that in character creation or actual advantages to specializing in it. It's a challenge run.
I breathe in ketchup and breathe out anxiety