non-prefixed global partitioned indexes are not supported because they don't have application in reality. Why is it so? Can it be explained with an example.

As per my understanding of the concept, I feel it is possible to have non-prefixed global partitioned index.
Suppose we have a table sales with columns:
week_no----values r like 1,2,3,etc
sales_amount---total sales in a particular.

Suppose we create a partitioned table using week_no as partition key and partition is based on range in slots like 1-4,5-8,9-12 week_no.
Then we can create a non-prefixed global partitioned index on cloumn sales_amount of table sales that is range partitioned in slots like values less than 5000,10000,15000,etc.
I feel such indexing would be useful in certain scenarios. I have also created such an index.

Please correct me if I am wrong on concept or misinterpreted something.