Try Wakfu. There are a lot of chill trades to grind casually and the economy is completely player driven. There are no NPCs to buy or sell your loot to.

The PvE gameplay loop is really fun. The game has an adjustable level system that encourages players to replay lower level dungeons. Battles are turn based and have a surprising amount of strategy.

The only real problem with the game is that the devs seem to not care about player growth at all. They do zero marketing and sometimes the registration system is broken and won’t get fixed for awhile. It’s like the opposite problem to RuneScape.