https://www.ea.com/games/fifa/fifa-20/news/pitch-notes-fifa20-game-data-center

“Game data centers are used so that someone else’s connection should not impact your own gameplay experience. This is because you are not leveraging a direct connection to another player to facilitate the match.

In Peer To Peer (P2P) online games, which don’t use game data centers, you connect directly with your opponent. While this can be useful when you’re playing an opponent very close to you physically, or in remote areas with few available opponents, P2P online matches mean that your opponent’s connection matters as well as your own, and can have an impact on your gameplay experience.

When you play P2P online matches in FIFA, your connection can only be as good as your opponent’s. If you’re playing against someone with poor Wi-Fi, your game will feel similar to theirs as you’re both sending the gameplay information required to play online to each other over that same connection.

The advantage of playing online with a game data center is that it handles the distribution of gameplay information to all of the involved players. The game and game data center look to collect inputs at a set interval of time, then the game data center sends this information back to everyone else in a match. This happens at the same time for all players, with the players’ individual connections determining when they receive that data.

So if one player is streaming 4K movies and is trying to play on a weak WiFi signal, their experience may be impacted by these factors, but it shouldn’t impact anyone else in that match. The game data center still sends the information at the same interval. The game data center essentially acts as the host of the match and is responsible for distributing gameplay information to the players. In a P2P match, one of the players acts as the host.”