Not every sound is an animation, thats just the case for footsteps, a gun fire is not an animation, well it can be, but does not have to be. Other sounds are pickup items, throw items like interaction sounds, or if something explodes.
You can probably bind a large part of sounds to animations, but I don't think it is a good solution to always need an animation to trigger a sound which then triggers something else, it should be within the sound itself.
Another problem especially regarding footsteps is, that since the footsteps are animation triggered you can use an exploit to be able to run without causing footsteps and this is through skidding, this works that way, that you press walk and look where the animation plays and then you only slightly press the walk key so that the animation only plays for a little bit every time without ever hitting the animation point.
Well you can avoid this mostly by placing the footstep at the first frame, but this will lead to cause the footstep sound to happen far too often and will cause funny looking skidmarks from the footprint decals created if you just press the forward key a lot and not hold it pressed and of course the footprints will not match the animation where the foot really hits the ground.
It may work for a quick and dirty solution if it only affects some form of sounds like footsteps, but thats not really what I want. Also footsteps happen quite often, like 2 times per second and more and I don't know how good for performance it is to check for every player on every footsotep if any other player is in range and then do something, it should be more like a on/off thing, like causing footsteps = 1 which is set to 0 when the player stops or sneaks or whatever.