It was not made in 2018, that's just the latest renewal of the ruling (which was originally made in 2010). Apple's attempts to make it illegal were denied at the time too, because even without the ruling it fairly obviously falls under exemption.
The ruling also just makes it explicit, the DMCA already doesn't cover things like jailbreaking because they don't relate to copyright, and do relate to the user enabling interoperability of their device with legally obtained software (17 U.S. Code § 1201 (f)). These rulings are not proclamations in contrast with the law, they are bound by it and must be valid interpretations of it. Apple's attempts to classify it otherwise were a clear attempt to abuse copyright law and were rejected as illegitimate.
You clearly do not know what you are talking about.