Though PgBouncer provides similar information regarding both server and client database connections, the status and health of each pool are also available. If we didn't already clarify, PgBouncer pools are separated by username, database name, and the server's hostname. Thus, each PostgreSQL server may have as many connection pools as there are different databases a user might access via PgBouncer.
PgBouncer supplies somewhat detailed information when seeking server or client status. However, these are not database views, so we can't summarize or aggregate the output to make it more usable. When running a highly available database server, we need to monitor aggregate values if possible to watch for potential patterns of misconfiguration or abuse.
Unfortunately, since PgBouncer acts as a proxy, we can't rely on the pg_stat_activity...