Unfortunately, #gcloud CLI does not have native support for multiple profiles when it comes to programmatic access to the #GoogleCloud API.
As in, you can't say
aws s3 ls --profile dev-eu my-bucket
If you stick with the default behavior, you will be forced to login to Application Default Login (ADC) every single time.
That's annoying AF.
That's why I created a small Shell #script to address this shortage.
https://gist.github.com/meysam81/5434245473479037d682eb2a12cf0cce