Yes if they do bludgeoning piercing or slashing. Not if they do fire, cold, poison, acid, psychic, necromantic, spell, magic, etc...
There are just a lot of creatures that simply don't do non-magic bludgeoning piercing or slashing damage. I am not saying there are not also plenty that do, it's just that as your levels increase, it seems the utility of the feat decreases a lot. You face more challenges that the feat doesn't apply to, and those challenges it does apply to make the -3 damage so minuscule as to not be really all that helpful. The feat is most useful at lower levels, or versus large quantities of lower level (often humanoid weapon-wielding) creatures at higher levels.
If you are facing a horde of kobolds or goblins, it will help a LOT. If you are facing a dragon...it's nearly meaningless. So it's situational. Which is not a bad thing, it's just a thing.
Ahh, my bad. I thought maybe you were saying that the feat only appiled to manufactured weapons, and thus creature attacks were not affected. Which is an argument I have heard brought up...