This is IMO just bad faith sealioning, you can look at the whole replication crisis in psychology and social science (esp. the work of people like Nick Brown and the GRIM test, or Uri Simonsohn), or sites like Retraction Watch, and see clear evidence of everything I am saying. There are endless papers in ML research going into issues with test datasets and data duplication, etc. In plenty of cases all data and code is made open, so it is trivial to check data issues and methods.

Also, review is back and forth, and has rounds: you almost always interrogate the scientists of the paper you are reviewing, this almost like the definition of peer review. I don't think you have any idea of what you are talking about at all.

EDIT: Heck, just hop on over to https://openreview.net/ and take a look at the whole review process for some random paper (e.g. https://openreview.net/forum?id=cp5PvcI6w8_)