For me the most important advantage of blind review is not that 100% of papers are effectively blind, but that if you're a noname author you have the right to b

For me the most important advantage of blind review is not that 100% of papers are effectively blind, but that if you're a noname author you have the right to be blind and not having your paper looked down on just for that reason. That alone justifies double-blind review. Regarding papers that cite proprietary datasets that no one can access, in fields like AI where it is perfectly possible to release datasets (if there's a specific reason it's a different issue), as far as I'm concerned they should be outright rejected due to lack of reproducibility and inability of the reviewers to check the correctness of the claims. Although I know this is a minority viewpoint and it won't happen.