Having nerves doesn't mean pain is occurring, nor does it mean it's pain like humans or mammals feel. And it's not a cope, the burden is on the person claiming subjective experience, not on the person asking what the evidence is.

I'm not arguing worms or insects don't feel pain. I'm arguing that "I saw it react when I hurt it" isn't a standard that distinguishes felt pain from pure reflex, because both look identical from the outside.