The issue here is that if company.com does not use Google Workspace and hasn't claimed company.com, then any employee can sign up for a "consumer" Google account using [email protected].
There are legitimate reasons for this, e.g. imagine an employee at a company that uses Office365 needing to set up an account for Google Adwords.
There are legitimate reasons for this, e.g. imagine an employee at a company that uses Office365 needing to set up an account for Google Adwords.