There are plenty of games like that where you can just perpetually play without following any clear objective (X4 games, Terraria, Stardew Valley, No Mans Sky, Elite Dangerous, Factorio, Dwarf Fortress, etc). However i don't think those are the types of game you want.
You probably want something with engaging and well developed side-quests, with interesting story and world building, casual friendly, and then having those going on forever in the world. In that case the answer is 'no', since you'd need either procedurally generated quests which are rarely interesting in the way people want them to be, or designed quests that would keep repeating itself with maybe some slight variations.
I could even suggest stuff like Dwarf Fortress or Daggerfall, which are close in concept but i doubt those would satisfy you.