if you look at this tweet

https://twitter.com/lonnibesancon/status/1488409297860153345

..." The series in which this is published does not peer-review, and contains all of the last authors' work... ... that major papers are omitted in this "meta-analysis" "

So no peer-review,

written in a journal that has close ties to one of the authors

and omitted major papers that should have been included.