Let's take a little break from the current day to discuss some of the history of FPS networking.
In the early days of FPS PvP games (i.e., back in the days of Quake), they were sometimes implemented using a pure client/server networking model. In a pure client/server model, all of the calculations about the game are done on the dedicated server and your console is relegated to being mostly a 3D rendering engine.
This is not how things work in either Destiny 1 or 2. In both games, every console is calculating all of the physics for an entire Bubble all of the time. The reason for this is that you want a first-person shooter to be very snappy. You want the bullets that you shoot from your gun to hit the target now and not half-a-second from now. When you cancel your jump, you want it cancelled now and not half-a-second from now. This is very important for an FPS game to feel visceral, real, and snappy. I.e., for it to feel the same w