Logical Backup strategy in large Oracle Databases
With RMAN you can do point-in-time recovery (if properly) configured, so you could restore the database to the moment before the drop. Also, you can even restore just a single table from a backup. Other than that you have the recyclebin from which you can recover dropped tables and you have also Flashback Database. So to recover from a dropped table there are plenty of options - without an export.
In my career I have only once used daily exports as part of the backup strategy, but we stopped that once you could restore a single table from backup.
Regards,
Daniel