“Instead of refactoring the architecture, AWS did what AWS does best - it built a new service.”
AWS bolted cross-account access onto IAM roles instead of fixing the model, so “role” now means three different things. GCP ties permissions to where a resource lives and lets them inherit. Plenty of companies still run prod, staging and dev in one AWS account and hope for the best. Complexity is the security hole. AWS sells you more services to manage it.