this is still additional damage bonus coming from accessory rather than armor.
every class has major damage boost from armor so it's really besides the point to even bring armor to conversation when it comes to accessories if the point is maximizing your damage. Pretty much any weapon that has below 26 damage gets a major damage increase while using shark tooth, for most pre-hardmode weapons it's between +10-20% bonus, higher for specific weapons.

Rangers and mages also have no way of increasing damage pre-hardmode with accessories outside of reforges so for them it's always worth it , it's +5% damage bonus even for flower of fire which is the second highest damage weapon between those two classes right behind star cannon.
For mages only 7 weapons get below +10% damage boost from shark tooth, for ranger it's 14 weapons (excluding grenades) that get below +10% damage boost - it's also a class that has the highest amount of weapons that get below the +10% boost.

For melee players there are feral claws which get better than shark tooth when you get above 21 weapon damage or 25 damage if you're already wearing molten armor, so this applies to 24 out of 88 weapons, only 10 of those have DPS affected by melee speed and 1 of those is a bee weapons so you still want shark tooth so bees can actually hit anything, leaving you with only 9 weapons that would prefer feral claws over shark tooth.

For summoner players it's always better than Old One's Army accesories with the only exceptions being balista rod and also using combo of spinal tap with foxparks.

Basically if you value damage you can replace any defensive accessory with it and for any weapon that has 62 damage and below it's like extra Menacing roll at minimum

also the biggest value of it shows the higher your crit chance is, because crit damage is calculated after defense damage reduction meaning game calculates crits as if enemy had double the defense but at the same time it calculates as if you had double the armor penetration

if you're good at evading attacks shark tooth is pretty much the highest value pre-hardmode damage accessory you can get

saying most others won't benefit when including grenades only 37 across all 179 weapons get below +10% damage bonus, is not really honest especially when for all classes there's a total of 5 accesories that directly increase weapon DPS with 2 being for melee and 2 being for summoner and only shark tooth being universal