Helps Maximize manufacturing resources when no longer relying on other countries. Example: Nazi Germany disconnected trades from the United Kingdom and other European countries then put a type of Autarky to maximize their manufacturing amount before they started WWII.
Helps countries that are isolated from other countries. Example: North Korea was disconnected from all trade in 2012-2013 because of Nuclear threats from North Korea so North Korea used Autarky to keep people alive in their country because they really relied on Imports to live
Cons
Sooner or later the country using Autarky will need aid from other countries. Example: In countries like Afghanistan and Iran they were under the control of the Taliban and needed aid from other countries like the USA for help.