Counterpoint, fire was historically used to drive away predators and is commonly depicted in movies as well. A random townsfolk may not know all the particulars, but put fire between the bad thing and yourself is a reasonable strategy for most monsters. It becomes a metagaming problem if it’s only done against monsters that don’t resist fire.
Oh, sure, you could absolutely make a case for your character accidentally stumbling on the right answer simply because fire is a good weapon, and a good roleplayer could use that to their advantage to metagame a bit more acceptably, but there’s a difference between that and just automatically grabbing fire stuff because you the player know it’s good against trolls.
Counterpoint, fire was historically used to drive away predators and is commonly depicted in movies as well. A random townsfolk may not know all the particulars, but put fire between the bad thing and yourself is a reasonable strategy for most monsters. It becomes a metagaming problem if it’s only done against monsters that don’t resist fire.
Oh, sure, you could absolutely make a case for your character accidentally stumbling on the right answer simply because fire is a good weapon, and a good roleplayer could use that to their advantage to metagame a bit more acceptably, but there’s a difference between that and just automatically grabbing fire stuff because you the player know it’s good against trolls.