I think you're confusing what the default VPC actually is. Most people would consider it anti-pattern. Back in the days the concept of a VPC didn't exist in AWS

I think you're confusing what the default VPC actually is. Most people would consider it anti-pattern. Back in the days the concept of a VPC didn't exist in AWS, so when it was introduced they also introduced the concept of a default VPC for new accounts. All new resources was created into by default in order to make it easier for people to keep working as they were used to. It only has a single subnet for each availability zone, which is connected to an Internet Gateway, effectively granting all resources with a public address assigned to it Internet access. That combined with the default security group was a recipe for unintended consequences. One thing I'd recommend is reading up on the Well-Architected Framework[0]. It approaches all the essentials in AWS and will likely save people from reinventing the wheel badly. There are aspects of the Well-Architected Framework that I don't follow, but those aspects become very clear when you understand what they're trying to make you do with it. [0] https://aws.amazon.com/architecture/well-architected/ https://aws.amazon.com/architecture/well-architected/