This is supported by MinIO, but not "as a service." Essentially you run MinIO everywhere (AWS, GCP, Azure, IBM, on-prem, OpenShift, Tanzu etc). In the public clouds you can either roll your own or use the marketplace offerings.
In effect, you are choosing MinIO object storage over the "stock" object storage (which is incompatible with the other clouds).
You can use MinIO's ILM policies to replicate, tier, etc.
You still pay for compute, network + drive but then pay MinIO vs. S3/Blob. There will be no egress fees.
Many companies that do this look at MinIO for object storage. Given they run in AWS, GCP and Azure, they will minimize or eliminate your application rewrites. They are cloud-native by design and very fast.