I play with Autonomy on, but I switch regularly between sims, so it's helpful to have the sims I'm not controlling actually do stuff on their own. Like Rouensims, I'll cancel if the sim wants to do something either out of character or disruptive to what I want them to be working on, but I don't watch my sims like a hawk either, and I'll roll with it - at least once they get done with the actions I want them to do.
In my current save I have two siblings living together with their respective kids, and one of the two teenagers has taken to watching out for his toddler cousin autonomously. He's put her to bed, read to her and all the usual "parenting" stuff, all without being designated her caregiver.
It's always interesting to watch what my sims do when they're not under my control, but at the same time, I'm telling myself a story, not watching one unfold. And while my characters in the sims - just like my characters when I'm writing - may do things that surprise me, ultimately, they do what I want them to do.