Don't try to equate living beings with non-living things. Doesn't work.
My argument is that all living things can feel pain, regardless of how it manifests for them.
It is not an argument. It is a statement. OK. What about short DNA fragments in a solution of DNA replicase. They are built from DNA, they are replicating, in a few billions years they can evolve, they aren't much more complex than a toilet bowl, undergrad molecular biology student can create them by billions.