It's one thing to say that you can't CNC machine guns for customers of your CNC-on-demand service, it's another to say you can't sell CNC machines because someone might use them to make guns.
Here the DNS service is being told they can't direct traffic to pirate sites, not that they can't give out tools (e.g. browsers or local DNS resolvers) that could be used by someone else to direct traffic to pirate sites (or could be used innocently). Your examples are all the latter - tools.
And yet some places (California for instance) are attempting to do just this by requiring some kind of vaporware AI mediator to review files before the machine operates. Intermediary liability is out of control.
It's not illegal to sell these because it would be illegal for the end user to make a gun with them (it might or might not be - but is irrelevant) - it's just illegal to sell them because the legislator said it is.