i second this and i think it became more efficient for holy sword to just kill the monsters faster than to lead them to a trap, maybe he has debuff traps so they did it for strong monsters or larger groups of mobs but even then because of the level difference his trap damage wouldn't be worth the extra work....and again that is only because holy sword didn't let him level up enough.
ultimately traps are time consuming and take alot of effort to get them to work at their best.
It's also something I see in RPGs a lot (especially TTRPGs):
Killing enemies fast is almost always preferable over any other option. If they die fast, you don't need as many healing or recovery resources. If they die fast, you don't get hit as much which is
generally than taking less damage when you
are hit. So in the end, DPS is king.
So if you have a party composition, there's almost always a realistic maximum of how many people you can bring. Even if it's not 'hard coded' (like in a video game), there still is always a point where any more just get in the way. So you want each member to be as effective as possible.
So when a situation comes up with a Buffer/Utility character, the question is: Do the benefits they bring outweigh whatever they're replacing? Why bring them instead of just another DPS? If you want added safety, bring another tank or healer. If you need more DPS, why not bring another DPS? And in most systems, the answer to all those questions is "No, just bring the DPS/Tank/Healer/Whatever instead of the buffer".
And that's the issue with the trapper character: If he's not making the group significantly safer, and his damage is piddling, why bring him at all? At best he's less effective than anyone else you could bring, and at worst he's a liability since he isn't effective
and is a drain on party resources.