Acamaeda
Terrarian
This is as much a suggestion to the developers as it is to people suggesting Post-Moon Lord stuff.
Right now, a whole tier of progression is based entirely on Moon Lord drops. The armor and many of weapons outclass everything else in the game. The problem is that if this goes from optional post-game content to just another tier of progression, it will mean that everyone will have to fight the Moon Lord multiple times to get the armor and (for most classes) weapons for whatever comes next, or suffer the consequences of being underequipped.
There is never any other part of the game where fighting a boss multiple times is the only viable way to progress for all classes. For a couple of classes, this kind of happens, but it's a choice what class you play.
The solution would be to have Moon Lord-tier gear become available in other areas after his defeat, which is balanced to be doable with pre-Moon Lord gear. This could be stuff that the Moon Lord currently drops, new things, or a combination. Having another way to acquire Luminite post-Moon Lord would also be a great help. This is all sort of like how early Hardmode gear is balanced to be obtainable with pre-Hardmode gear, even though Wall of Flesh drops can be a great help. Having many different ways to progress is a huge part of Terraria, and losing that would hurt it a lot.
Tl;dr You should be able to get Moon Lord-level gear in other (still challenging) ways after beating the Moon Lord so you don't always have to fight him repeatedly to progress.
Right now, a whole tier of progression is based entirely on Moon Lord drops. The armor and many of weapons outclass everything else in the game. The problem is that if this goes from optional post-game content to just another tier of progression, it will mean that everyone will have to fight the Moon Lord multiple times to get the armor and (for most classes) weapons for whatever comes next, or suffer the consequences of being underequipped.
There is never any other part of the game where fighting a boss multiple times is the only viable way to progress for all classes. For a couple of classes, this kind of happens, but it's a choice what class you play.
The solution would be to have Moon Lord-tier gear become available in other areas after his defeat, which is balanced to be doable with pre-Moon Lord gear. This could be stuff that the Moon Lord currently drops, new things, or a combination. Having another way to acquire Luminite post-Moon Lord would also be a great help. This is all sort of like how early Hardmode gear is balanced to be obtainable with pre-Hardmode gear, even though Wall of Flesh drops can be a great help. Having many different ways to progress is a huge part of Terraria, and losing that would hurt it a lot.
Tl;dr You should be able to get Moon Lord-level gear in other (still challenging) ways after beating the Moon Lord so you don't always have to fight him repeatedly to progress.