I can't remember a lot about this book. However, I remember a guy going to another world or maybe stuck in a game. He gets a bracelet with slots that gems go into, which gives him major power. The bracelet was cursed or something, and it tried to sap his will and take over, but he managed to conquer it. He starts in a town and does every quest he can. Then a shop owner shows him a special item that that boost max stats but costs way, way more than he has.
The main character (MC), Jack Halberd, has a dying uncle that disappeared for 40 years. The MC puts on this bracelet while visiting his uncle and is transported to a medieval world where he’s Lord Halberd and has magical game powers that he’s supposed to use to build a kingdom and defeat the evil bad guy.
Your description fits the usual LitRPG template where people are basically following RPG game mechanics whether it's explicitly acknowledged or not. You have the cursed bracelet. You have the other world that he's transported to. The reviews mention the incessant questing (generally alongside notes that they feel that the villain was dumb to just sit back while the protagonist grinds his stats).
Found via a search for LitRPG cursed bracelet on Google.