Ermmm....No.  Try putting an index on a multi-petabyte table and see how far it gets you.

RedShift may use a Postgres implementation but it isn't RDBMS, it's a column store.  A clustered index may help a range scan if the fields in the index are what you are scanning on but column stores work on differently to OLTP databases.

Not all Big Data tools are databases.  Apache Spark and Beam are distributed compute engines.  These are serious tools, not the usual seasonal fashion.