I completely get this. Never really thought of it the way you post, but I get it.
I am a multi- tasker where tv is concerned too. Sometimes it is just nice to have voices in the quiet house. The one and only show that gets my full attention - law and order: SVU.
The way I see it, is that its comforting. So now I know i sound crazy, but hear me out.
I don't talk about what has happened to me. I don't remember all of it. And I've often gotten sub-par responses from people I have sought out for help.
Watching it is a safe way to start to work through things even if you don't remember them. And even if you have never been abused, things come down to the emotions. You noted rape and child abuse - both situations where the victim has a complete lack of control. A feeling very triggering for you.
And you may not be able to feel sorry for yourself. You may not be able to empathize with your younger self. But you can feel and empathize for this fictitious character who is some way reminds you of you consciously or sub consciously.
Sometimes I call it triggering myself. I know I am looking to be upset, to feel triggered. But it is in a way that is distant, and in my control. I hold the remote control. I know its tv so whats the worst they can show. And I know that I can turn it off if I need to. I can't deal with my issues. I can't deal with the big picture. But watching this it just does a little bit. Its just little enough that I can handle it. And feel some of those emotions in a controlled way.
And then see the "happy ending" (loose term) when the victim gets the help and support they need. And they get justice. I see it like desensitization (a behavior therapy technique). And I think it is very normal. And it could be very helpful with your healing. Sorry for the super long response. Hope this helps.