It handles also load_balancing but it can be disabled : "load_balance_mode =off "
I recommend pg_pool v4.2 (at least) , much more easy to configure (same config file on all nodes).
I already use it as a HA solution between 2 nodes (with PG replication), but be careful with some parameters : " failover_when_quorum_exists = on failover_require_consensus = off
Currently my customer has some very large stand-alone PostgreSQL 9.6 (will migrate next year to v13) databases, and they want to add HA.
Specifically, they want a "cluster name" which points to a Primary database server's IP address, and and which automatically (presumably through through a heartbeat and quorum voting system) points to a Secondary database server's IP address if the Primary server goes down. Both servers are in the same data center. (Replication would be handled by a standard PostgreSQL method.)
This is not load balancing, but a purely HA solution.
I looked at HAProxy, but it seems to be focused on load balancing, while the Patroni documentation does not seem to mention a cluster name.