My main use case for Upbound Crossplane is that initially we were frustrated with using Terraform, and right now all the infrastructure provisioning and infrastructure automation we are doing is through Crossplane.
A specific example of how I'm using Upbound Crossplane for infrastructure provisioning and automation is that currently, for our platform, we have a cloud native GenAI platform, and for that platform, we have to provision various services in three hyperscalers: AWS, Azure, and GCP Cloud, so across all three major cloud platforms, we have to provision our resources using Upbound Crossplane and it is easy to manage them.