I disagree, the strong points of debian are the stability (long periods of testing, without new changes) and security (by applying security updates quickly).
Using testing or sid means to forego the strong points. At that point you are better served by other distros which focus on having newer packages.
Also i would be cautious about using Debian testing (forky).As far as i know its the worst in terms of security. Stable has security update priority over testing. And some people say even sid it's better on that front by having even newer packages.
Disclaimer: I daily drive debian stable and game on it without hiccups. Rock solid. BUT i have 7 year old amd rig and the games are not demanding.