I’ve read a manual, configured and tested some pgbackrest setup and I’m a bit confused on how much WAL files pgbackrest keeps.
I’m wondering what is the advantage of having daily incremental backups (and full weekly) vs daily full backups? And why pgbackrest need to keep that much WAL? Even with the minimum retency configuration.

My sample database is 50GBs with around 100GBs of daily WAL files. Full backup takes 5GB while pgbackrest keeps more than 10GB of WAL files between each incremental daily backups!
It takes briefly shorter time for backup to be taken, but the disk space usage is way higher in that strategy.

What are the pros that I don’t see?