Analyzing and demonstrating problems with an accepted but potentially ineffective / suboptimal treatment method does something to resolve the issue in terms of illustrating the need for new methods thus making room for new research & development.

Not everything needs to be constructive. You sound like you don't appreciate this kind of work. I don't see a problem about this "not being new" nor being "just a meta review".

Should scientists "shut up unless they have new or good things to say"?