Fact: I play BF3, but would rather play PS1

[Captain1nsaneo]

Immersion is created in a game by setting down rules as to how the universe works and then rigorously adhering to them. The cause of immersion in PS was the sense that everything had a physical presence and actually took up space. Conts are large and have travel times as you can't just teleport a physical object somewhere. Recall and Instant Action both adhered to this as well as when you did them your body deconstructed which was itself a mechanic for explaining where the things went after they stopped taking up physical space.

Vehicle entrance/exit animations were just an extension of this logic as to get into a vehicle you need to resolve that two objects with that take up physical space are now occupying the same space. PS actually does have the instant enter/exit of BF but it adheres to PS's internal logic. The AT vehicles all effectively make you disappear when you enter them. It doesn't break immersion because you see your character dissolve like you would if you recalled. This is the genius of PS's immersion, always explaining or showing the transition of objects between in-game states.