Short answer: It's not that simple, but yes.
I think that a developer needs to give the player a sophisticated, disbelief-suspending, and unobtrusive reason to act in the world you're in, regardless of if the game is open world or not. Whether that equates to a simple story, a complex story, a deep story, a shallow story, or no story at all depends entirely on the context the game gives you.
If I'm playing Mario Bros., saving the princess does those three things.
If I'm playing Street Fighter, the mechanics do those three things.
If I am playing a Earthbound, its simple plot does those three things.
If I'm playing an open world game, and there's a clear attempt to introduce lore and world building of any kind, there needs to be a story there that matches the complexity of the lore being provided, and it needs to be compelling enough for me to want to play through it.
That's why the Elder Scrolls fail to me. They don't do those three things. The reasons Bethesda gives its players to traverse their worlds aren't sophisticated, they don't make me willing to suspend my disbelief, and they are completely obtrusive to the experience; if someone choses to play through the story of Skyrim, they are actively anchoring themselves to an inferior play experience that runs counterintuitive to the world and mechanics the Bethesda has provided you with.
The fact that Skyrim is synonymous with mods is proof of this. Again, this varies from game to game, but in order for a game like, for example, Skyrim to work under these qualifications, the game needs to provide the player with a way to want enjoy the plot without it clashing with the mechanics and playground provided to you.
This largely would suggest that the story be extremely none linear, and likely very simple, instead relying on well written, world building side quests to fill in the meat of the experience, not unlike something like Majora's Mask. Many open world and sand box games don't achieve this well, and suffer as a result, because your actions aren't framed well and don't feel meaningful.
