The problem with using phages to treat Borrelia is their variable genome, exchange of genetic material and the fact that no two Borrelia are alike in living hosts (as opposed to lab cultures).
One would have to engineer an array of phages and give them all each time. Even with this, some bugs may escape.
Some feel there needs to be evidence that matches the extraordinary claims.
Some medical reviewers approved the initial paper. When I did that for six journals, I would have required much higher clarity. I found it very confusing.
I do not oppose this very different type of phage infection treatment has been used for decades.