We do not know what the CIA told Biden and other policy makers. The CIA is not responsible for the incompetence and poor decisions of the country’s leaders.
They have a track record of publicly confirmed failure as far back as you want.
-surprised by the Korean War
-Vietnam, Laos and Cambodia follies
-surprised by Yom Kippur war
-totally missed the collapse of the Shah
-totally missed the USSR Afghanistan invasion
-wildly overestimated the USSR economy
-911
-”weapons of mass destruction”
-ISIS is a JV Team
-...