The cost benefit is really poor, but I also wonder if it's just never been done well.

Old text adventures honestly did this heaps better than modern games do, but the reality is there was a more finite action space for them and it wasn't surprising when something wasn't catered for.

Which games are these? I’d be interested in checking them out.

I’m only aware of experimentation in making more “difficult” NPC AI which was found less enjoyable for obvious reasons, so would be interested to see why similar but different attempts down another path also failed.