Why do players gain control over items in map over time

i was watching this video on exploits, go to 5:07

why is the players area growing and what is the point of this? why is it gaining more control

Replicating Physics to all Clients

ROBLOX’s Network Ownership system relies based on a few measures:

If an object is not owned by any client, then the server owns it. When the server owns Network Ownership of a part in your game, then no client can interfere with it and all changes made from that client, will replicate to that client only.

For ex: Your character BodyParts Network Ownership is Client Owned (you), and a random object is going to be Server Owned until you get close enough to it (then you get Ownership), unless if you have a script that sets that Network Ownership to the server (nil) then it’ll stay on the Server. (Client = You, Server = the game, but only what replicates to all Clients)

Server replication obviously will replicate to all clients (for server actions/events only).

Now if an object is owned by a client, then that object will respect what that client does. If the client grabbed it and dropped it, the Physics will simulate still, but for other players, they will more than likely see choppy/laggy physics occur for that part. This is because the Physics rely on that Client’s behavior and networking.

You can read about it more here: Network Ownership | Documentation - Roblox Creator Hub

Here’s my guess:
That distance grows because as time progresses more parts are likely to become relevant to the nearest client. The physics adoption improves the accuracy for that client and lessens the load of any active physics for the server. The growth is dynamic load balancing. Running physics for all assemblies is divided amongst clients so the server doesn’t struggle with that task.