First, if you consider specs to be an answer to snorlax, also consider trapinch can trap a specs thunderbolt and kill jolt/ magneton easily.
Second, trapinch traps and ohkoes not only snorlax but also chansey.
Third, if somehow the opponent has not any of those two, in some circunstances you can sacrifice a pokemon u wont need to sent full health trapinch to trap a scouted joolteon with leftovers, or magneton without life ball. Trapinch also ohkoes defensive arca this way without being ohkoed bu hit.
Lastly, quick attack banded hurts anything not tanky, and is useful for late game clean.
Trapinch is much more useful than you think.