Database Replica object are only valid for secondary?

Question

Hi I'm analyzing metric on this page

https://learn.microsoft.com/en-us/sql/relational-databases/performance-monitor/sql-server-database-replica?view=sql-server-ver15
and in the abstract I read "...This object is valid only on an instance of SQL Server that hosts a secondary replica."

Is it true this? 'Cause I see on the header "View on..." and there is "Primary replica" also.

For example, I understood that the last one metric "Transaction Delay" is related to primary...
"Total delay in waiting for unterminated commit acknowledgment for all the current transactions, in milliseconds"

I interpret the last column as the reference to read the data where it is specified.
Can you clarify me?
Thank you