I think maybe just stating the obvious is something therapists do to try and create understanding being the client and therapist.

Or she might have said "everyone does X" to try and normalize whatever you were discussing. Sort of like, "everyone masturbates, but no one talks about it" type of situation where it's sort of taboo to talk about it but speaking to the truth of it could bring bring relief in knowing you're not some weird anomaly.

You asked if anyone found the approach helpful: I do, at times. When T tells me X is a common response from X, it makes me feel less of an idiot and it's harder to put myself down for my "normal" responses.

I'm not sure what you're meaning when it comes to intervention. Did your therapist actually say "intervention" ?