Is this something Pulumi could improve upon? https://www.bejarano.io/terraform-stateless/

There is an issue for this: https://github.com/pulumi/pulumi/issues/6667 The main problem is that while it sounds like you could just query the provider for all resources and match up by attributes, the vast vast vast majority of cases have multiple projects/stacks in the same cloud account. A stateless mode where the state is given by "everything returned by query for the current cloud account" means that you need a new account for every stack.

I had a similar though process, I wonder if that could also trigger provider API throttling hampering pulumi performance.