you got (2) wrong, the reason is running code on S3 is insecure and would not be allowed and spawning VM inside S3 for some local calculation would be cumbersom

you got (2) wrong, the reason is running code on S3 is insecure and would not be allowed and spawning VM inside S3 for some local calculation would be cumbersome at best as it is too bulky for such acrobatics.