You have darklight gear and you have your relic weapon. What now? There's not really much to do. It gets very boring because everything is so static. There's no fun items and no fun stats. No point in doing dungeons anymore, all you'll receive is durability loss from trash. So do what? Coil? Why? For the same static gear again? Sure you might have fun with the boss fights but that's about it.
Level another class? Good luck not getting bored with 0 quests (props to those who have multiple 50s). Grinding fates may be fun for others but it's rather dull to me.
Level a crafting/gather class? For what reason? The things you make aren't going to be of much importance. So you sell some things and get money. What do you do with the money? There's nothing to spend it on. There's nothing fun in the market.
So what do you do?