Attribution does not exempt an author from the need to get permission. Baring a few edge cases, such as fair use, a copying without permission is still a copyright violation, attribution or not.

Plagiarism is not the same as copyright infringement.

"Plagiarism" is not a legal thing: it's not a crime codified in law and doesn't appear in laws [1]. Instead, usually it's a violation of some internal code, e.g. a school's or newspaper's policy of integrity. As you say indeed, usually these policies only consider something plagiarism if there is a lack of (clear) attribution.

However copyright is encoded in law and copyright infringement is a crime. The linked page clearly violates the copyright of OP.

[1] https://en.wikipedia.org/wiki/Plagiarism#Legal_aspects