Valve still uses Ubuntu as it's base for it's Linux game runtimes. Dev's are encouraged to use it for developing Linux games, since it guarantees specific dependencies being available. This runtime is a container which comes with Steam and works on any distro.
Valve basically solved Linux problem with too many distros with different deps.
Arch updates going bad is much more likely to happen if the system goes without updates for a long time. So I'd really not recommend it for a seldomly used laptop.
But regularly updated Arch is fine. Even if something breaks it's usually easy to deal with.