It's a long time since I played GTA5 but I think that had an in-engine animation sequence for getting in & out of cars (ie transitioning from FPS to driving game). In practical terms the player presses the 'get in / get out' button rather than a complex sequence of movements to climb out of the SRV & back in. I agree that would be an improvement over a simple transition, and I suppose it would look odd to other players watching you if you just magically appeared outside your SRV. I've never watched the cockpit of a ship as a player chooses to enter their SRV, I guess the avatar in the seat just vanishes?
Good point
I am not sure either how it appears