Not everything my Ts say is insightful, but at times they have been able to pick up on certain points, or highlight patterns of behaviour, join dots... things I may not have seen for myself - at least in the moment. I like to think I'm pretty intelligent, but my Ts are smart people with expertise in their field and a lot more life experience than I have, so I find talking to them helpful. It can be good to bounce things back and forth (two heads are better than one?) and get a different perspective, be challenged, or even just validated,

I don't know about 'intervention'... I don't know that I would use that word to refer to my experiences in therapy, though I suppose it might apply.

At least in some forms of therapy, I think 'modeling' comes in as the therapist is supposed to model healthy behaviour and thinking patterns - demonstrating by example.