It really depends on what you enjoy out of an open world game, I've played Fallout 76 and have enjoyed it a lot since Wastelanders came out. It's got a lot that makes an open-world game an open-world game and a pretty good story to go with it, it's pretty good for an online game.
I love recommending Wurm Online/Unlimited, but it's not exactly a game for everyone. Way too much going on. Matters by what you want though. I like games with low or no scripted content and an economy or industrial thing. Satisfactory, Astroneers, Kerbal Space Program, so many others.