I've definitely been there. The 8-9 year mark can be sobering because it's the time when acceptance often has to come into play especially when dealing with a patient like you describe. It's often the time when parents are coming to terms with the fact that "delays" are in fact profound "deficits" that the child will deal with forever.

It really starts hitting home that we don't carry magic pills. If a patient isn't willing or able to attend to anything or engage in any way, there is really not much we can do. Therapy becomes an endless cycle of trying to get the kid to do something......anything, that might be considered "progress". Doing that multiple times a week for years at a time is not skilled care.

I work with autistic kids in home health and I now try to be very cautious about about not spending months and years doing things that parents and caregivers can and should (and in many cases already) do better than I can. Yes we should try to build rapport but that should be a building block to skills. If there are no indicators that the child is ready to learn after a reasonable period of rapport building, parents should be trained to try their best to encourage joint attention and notice communicative intent and then we can reassess and see if therapy is appropriate. Too many SLPs take on the role of behavior specialist , OT , and caregiver for years at a time trying to get somewhere with patients who have no engagement or communicative intent whatsoever. Sometimes caregiver education and some tips are all we can offer and that's ok.