More can be written on this.

Unfortunately, the FAQ section "Nazi Post-War Flight and Justice" has only one applicable title, and after the author deleted the applicable reply, it no longer answers "why".

You might like to start with

• "What prompted Argentina to provide safe haven for Nazis after WWII?" by /u/Brassafrax
• "Why did many Nazi officials escape to South America after the end of the second world war? What made that location so appealing?" by [deleted]
• "Why did so many Nazi officials flee to South America after the fall of the Third Reich?" by /u/nukular89

For Hitler's survival, there's an FAQed discussion "Did Hitler survive the war?" , with applicable answers by [deleted] and /u/Bernardito .

This is not to discourage discussion. More questions, data, and debate are welcome.