but I dont understand "Why" we would use Lisp...and even what else
A.I. researchers would use to do machine learning etc.
Yann LeCun developed Lush aka LISP Universal Shell. He also became Director of AI Research at a social media network recently.
Any articles/books on the subject matter is helpful too :)
I guess you already know Artificial Intelligence: A Modern Approach
It is the most read introduction book for AI at universities.