what's difference between setting policies on the broker and the namespace?

[zzzz465]

I'm using pulsar 3.0.0 and I configured pulsar broker like this

brokerDeleteInactiveTopicsEnabled=true
brokerDeleteInactiveTopicsMode=delete_when_subscriptions_caught_up
brokerDeleteInactivePartitionedTopicMetadataEnabled=true
brokerDeleteInactiveTopicsMaxInactiveDurationSeconds=3600

I expected unused topics will be deleted after few days ago, but they're still exists. also topic and namespace doesn't have any inactive topic policies.

1. why is the topic not deleted?
2. if I configure broker, will it remove topics from any namespace without any namespace / topic level configruation?