Neural and symbolic AI will eventually merge. Symbolic models bring much needed efficiency and robustness via regularization.
If you read PAIP today, the most likely reason is that you want a master class in Lisp programming and/or want to learn a lot of tricks for getting good performance out of complex programs (which used to be part of AI and is in many ways being outsourced to hardware today).
None of this is to say you shouldn't read PAIP. You absolutely should. It's awesome. But its role is different now.
Other parts like coding an Eliza chatbot are indeed outdated. I have read AIMA and followed a long course that used it, but I didn't really like it. I found it too broad and shallow.
My hunch is it emerges naturally out of the hierarchical generalization capabilities of multiple layer circuits. But then you need something to coordinate the acquired labels: a tweak on attention perhaps?
Another characteristic is probably some (limited) form of recursion, so the generalized labels emitted at the small end can be fed back in as tokens to be further processed at the big end.