I disagree with this perspective. You should have multiple accounts but only if your organisation requires it for isolation or data protection reasons and only enough to perform the task. Every other reason here is because you fucked up. You have poor architecture, poor tagging, poor VPC design, poor IAM policy and role modelling or don't know what you are doing to start with. And some of the stuff doesn't even make…
This is a bad take. Making good IAM Roles and Policies is incredibly complicated if you have a complicated account. You WILL get it wrong. This becomes much more tractable if you have reasonable account boundaries between workloads.
If you insist on a single massive account you're fighting against the way that AWS designs the system, and you're gonna have a bad time.