internet archive, although more easily archive.today, should make a firefox extension to archive paywalled articles from people who have subscriptions and release them in the future (5, 10 years)
Unfortunately, archive.today can never be trusted to have a safe Firefox extension. It is difficult enough to trust the site anymore after it was found that it was engaging in a DDoS attack against a different site. Imagine the hazard from an extension.
In the same spirit, however, it would help to have an extension that auto-archives unpaywalled versions of paywalled articles, and makes them auto-available to users subject to the paywall.
The problem with INMEDIATE pirated access of paywalled content is that it really hurts journalism. I mentioned archiving paywalled content for preservation and reference years from now.
You argument is invalid because nothing that is not available to the public is being hurt. Your argument is like saying that redistributing wealth really hurts rich people, so the poor shouldn't do it, and should just suffer being poor instead. Your argument would have merit only if unpaywalled journalism was being hurt, but it isn't.
In the same spirit, however, it would help to have an extension that auto-archives unpaywalled versions of paywalled articles, and makes them auto-available to users subject to the paywall.