aws cli output automatically being sent to vi

Just run your command with --no-cli-pager like so

aws ec2 describe-instances --no-cli-pager

You can also run a one liner command:

aws configure set cli_pager ""

It was the PAGER environment variable set to "less" (which I was confusing with vi).

This fix is to update the ~/.aws/config file and setting cli_pager to an empty value, e.g. :

[default]
region = us-west-2
output = json
cli_pager =

Thank you to Sorin who commented on my question lead me to the answer.