It is advisable to create a user for everything and do "nothing" with root
but it would also be advisable if you take a user as an example would be user "games" and then run on minecraft server ark server csgo server etc…
In itself, it would be nothing else than create new user.
But then there would not be so many folders in the / home directory, and you would not have many users for every single game server!
Personally, I would run any service (whether it be a game server, web server, etc.) under a dedicated user and if possible isolated from the others (for example via chroot or container technology).
For example, if your MC server is Compromised, you have to start first only there. Not synonymous with the CS: GO and Ark server.
A common user only makes sense if the same data must be accessed if necessary. Even a common group makes sense only if the servers poach each other in the data.
And even then, separate groups and users would make sense and fine-tune it with finer granularity.
No, the bid is the strongest possible segmentation. And as Barnim already wrote, where possible throw the process into a chroot jail.
