Can't increase APFS volume's size I've created a new partition on my Mac and deleted the previous one.
I can't find any way to increase the "Container disk1" size. 
Even if I try to reinstall the OS with recovery mode, it's written that there's only 100GB available on the disk.
Here is the output of diskutil list:

/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                 Apple_APFS Container disk1         100.3 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +100.3 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume macOS Playground - Data 50.0 GB    disk1s1
   2:                APFS Volume Preboot                 81.0 MB    disk1s2
   3:                APFS Volume Recovery                528.1 MB   disk1s3
   4:                APFS Volume VM                      1.1 GB     disk1s4
   5:                APFS Volume macOS Playground        11.1 GB    disk1s5
Rebooting in internet recovery mode and erasing the physical worked. Save your data before doing that.