People forget that arXiv is just an academic wikipedia. Anyone can post an "article" here. So a being "published" here is meaningless as to potential validity.

People forget that arXiv is just an academic wikipedia. Anyone can post an "article" here. So a being "published" here is meaningless as to potential validity. When referees at real journals actually do their jobs correctly, they check arXiv when given manuscripts to read & reject them if they have been posted to arXiv as violating the "no prior publication" rules at the real journals.