Hi, @Versus. You could separate the remote storage and cache by namespacing them.
You could add a DVC remote as a s3://my-bucket/dvc-remote and then everything will have that prefix. You could create multiple DVC remotes this way.
dvs remote listonly lists storages, not the contents of the storage.
It is better to use remote specific tools to visualize this. aws s3 ls can help you here.
is it better to have separate S3 buckets per project? Or one bucket, but separate folder for each artifact?
It depends on your preference and requirements, as DVC does not have any particular requirements.
You can use single or multiple buckets as you like. Or, use a namespacing with prefix and enable ACL.
You can even share a single remote across all of the projects. In that case, DVC will deduplicate your artefacts and data, but you need to be careful when using dvc gc.