Can you think of what makes this different from a TTRPG, specifically, in your mind?
Very generally speaking - the structure.
If you look at tabletop RPGs, you will see that they are essentially the same thing. When it comes to a video game RPG you need to be very specific about what you're putting in and how everything is going to work together. In tabletop you can do whatever you wish, because you can come up with literally anything, even when it doesn't make sense.
If you go for narrative-heavy cRPG, then the amount of content you can put it has to be done by hand and is ultimately limited, because your choices and their outcomes are predetermined. In fact, a lot of the time choices end up being "choices" (you use different skill, which leads you to the same conclussion).
If you go for a simulation, then the amount of content and choices should be greater and less restricted, depending on how detailed the simulation is.
Imagine the world not being both empty and static, waiting for the player to do something. This is a huge difference between a video game simulation and tabletop: tabletop rarely has the need to simulate events that happen outside of players' perspective. They are mostly static. Reactive, but static (the same way narrative-heavy cRPGs are static). And blank. Until there is the need to fill in the blanks.
Technically your GM could decide to introduce some sort of outside influence (NPCs being agents doing their own things that impact everything else, the flow of time being an important consideration, etc.), but that would make it harder to manage the game, so most people don't really bother with it and focus on the party and the reactive part of the tabletop, which means only what players interact with is simulated by their GM (and their imagination - and their GM's - is the main limit. The other main limit being GM's own willingness to roll with his players' choices).