Oracle on AWS RDS: is performance tuning no longer required?

Question

My customer recently migrated from on-premises to the AWS Cloud. With SYSDBA locked down, I am aware that the Cloud has taken over many of the manual responsibilities -- if not all. When I review the DBA_ADVISOR_RECOMMENDATIONS there are a number of tuning recommendations. I'm questioning whether PGA/SGA parameters should still be maintained -- or not? TIA