Everybody* loves gibs.
It would be useful to have at least some basic gibs that represent and can be attached to bipedal forms like lovable Terry and hopefully a human base too, but having a system in place to use those assets would please many people.
The 3D Fallout series has a large collection of small gibs for basically every body part and even insides, to the point you can make a whole person out of them minus the outer layer, and also detach any body part with its clothing still on. S&box doesn’t need gore to be this complex though.
Implementation
For example, when decapitating the head you could model a stump to be attached there to cover up the size 0 bone and then spawn a whole head(with the same cosmetics?) or bloody jaw and skull gibs to go soaring off. And blood could continuously squirt out and stain the ground. The same could be applied to any appendage, hopefully even on a living(in the game) person.
For clientside ragdolls whenever the server tells the client to create the ragdoll it could also provide gore data so the client can perform that. And by default the client may not be able to create more gore on those models, though this can be enabled. Serversided ragdolls could still have performance settings through Lua C# and CVars.
Settings
Since we’re all aware that plenty of children will play this game it would also be good to be able to tone it down and even warn you before joining a server that has a higher gore setting than you choose(None, Light, Extreme etc). Now little Jimmy doesn’t have to worry about playing S&box at school or work when he’s older.
And while gore is fun it’s probably not going to be critical to gameplay most of the time, so allow the client to turn down blood/particle and gib quality or disable it entirely if your computer isn’t up to the task or you just want more visibility.
Third party mods that expand gore features could use those default client and server CVars to manage their own performance/visibility to further appease parents, teachers, and people with beige computers alike no matter what server you’re on. This gives more purpose for it being a default feature.