it is open access, but often 'golden' or 'diamond' OA, where the researcher has to pay few K$ for this.

This is discussed in the article.

The article's discussion of how the open access mandate works is wrong. Federally funded research, when published (even in a closed-access journal) must be deposited in https://pmc.ncbi.nlm.nih.gov/ or a similar repository.

Edit: OA advocates have won pretty much everything we wanted, there's not much left to be outraged over.

But that's what the article says? The (correct) criticism of that system is that the publishers just replaced the subscription fees with article processing charges for OA publication, and still profit from public funding the same as before.