Every aspect of a modern game is specifically engineered to hold your attention as much as possible. They're really designed by mathematicians & based on game theory.
Flight simulators are boring, no matter what. There's simply no way to make a realistic simulation of flying to Mars also be a gripping arcade game. The problem isn't the models, the physics, or the sound, but the map.
So the 1st thing to go is realistic simulation. In its place, the traditional space flight game is a kind of "rail shooter". There's a track winding through a 3D space, where player input is restricted to just 2 dimensions on the track. The track has ramps to allow the player to jump in 3 dimensions by inputting only 2 dimensions.
On a PC, there are enough user inputs to allow 3D user input. There still needs to be a track the user needs to stay on, but the user can dictate height above the track. It's still a very circuitous route to Mars, but more entertaining than NASA TV. Haven't found any better way of modeling the track other than a series of rectangles. The flying properties of the BFR have to go, too.
The next thing modern games do is have a fuel gauge system. Each game consumes from the fuel gauge until they have to wait for it to refill. Once it's full, it stops filling until they play again. It's not about keeping them from playing as much as creating opportunity cost for not playing.
Finally, modern games have multiple rewards: credits, tokens, & cards. Credits are the easiest to get, determined by player ability, & create the least progress in the campaign. Cards are the hardest to get, are usually drawn randomly, & create the most progress in the campaign. You can't normally exchange 1 type of reward for another. The multiple reward system might be to allow a much wider range of difficulty than multiplying the price in credits by a billion. The campaign takes longer & keeps you engaged.