Uh, this is not an MMO. World of Warcraft is an MMO... key differences here are:
MMOs tend to have all players in the same server instance together reading from the same DB. Halo spawns out servers as needed per game launched and runs as a container or standalone vm. (would hope they are using containers at this point, most all others do minus MMOs). Game clients send updates at a much slower rate than FPS games, and they use backend databases and client-bound entropy for generation of randomized numerical draws when someone say, opens a chest or boss drops lewtz. Sometimes the random ID generation is done on the server, but those tend to run far, far fewer clients at the same time. The CPU load for floating point calculations would kill the box in moments, thus offloading to the game client uses open resources on the customer's end which they would not notice.
For an FPS like Halo:Infinite then all players are in a single instance of a game server sending updates to the game server at the determined tick rate that 343 sets up and uses. All updates from all game clients are shared to every player at that ticket rate util the game ends, then the container or VM is recycled or terminated. All compute is done on the client end only for the player whom is logged in and playing. Shots, coordinates of the player and aiming coordinates are generated and sent to the server during the match.
These days, so much crap like software overclocking, cheating clients, comms clients, and more run on the customer's end (do not even get me started on the hardware differences they have to code for) so for the few who post in here needing help, millions more play without issue. I would begin with looking to run as few services on your own machine that you care about, only run the needed drivers (remove old ones), clean your OS up (bc I am sure you are not on Linux), then turn off your RGB controller apps and play with only the minimally required items running, and I would bet good money things would be fine.
Cheers mate.
