What is the performance impact of pg_stat_statements?

I am using pg_stat_statements to find the slow queries in my production PostgreSQL 13. Two things: - I am unsure of the performance impact of this extension. - Is there anything I can do to improve its performance? The query below takes > 1s - any suggestions?
-- add the plugin create extension pg_stat_statements; select pg_stat_reset(); select pg_stat_statements_reset(); and then: -- find slow queries using the extension: select * from pg_stat_statements order by total_exec_time desc limit 50;