MacOS – 2015 MacBook Air: Internal SSD Is Locked and Can’t erase/update

Have Early 2015 11" MacBook Air, with original 128GB SSD installed. Running High Sierra 10.13.6
Filevault has never been on.

Computer crashed, and upon reboot, progress bar gets about 3/4 of the way through, and then screen just goes dark.

Am able to boot into all the various recovery modes, but in none of them is DiskUtility able to reformat the internal SSD drive, as it is showing as not writable. I created a boot USB with High Sierra 10.13.6, and can see the internal SSD drive and copy files off the drive, but it is not writable.

Any idea what's going on, and what else I can try?

Here are some various diagnostics:
diskutil list

/dev/disk0 (internal):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                         121.3 GB   disk0
   1:                        EFI EFI                     314.6 MB   disk0s1
   2:                 Apple_APFS Container disk1         121.0 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +121.0 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD            90.7 GB    disk1s1
   2:                APFS Volume Preboot                 37.9 MB    disk1s2
   3:                APFS Volume Recovery                515.1 MB   disk1s3
   4:                APFS Volume VM                      8.6 GB     disk1s4

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *61.5 GB    disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS Untitled                60.7 GB    disk2s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk2s3

And some more info:

steves-MacBook-Air:~ sjs$ diskutil info disk1s1
   Device Identifier:        disk1s1
   Device Node:              /dev/disk1s1
   Whole:                    No
   Part of Whole:            disk1

   Volume Name:              Macintosh HD
   Mounted:                  Yes
   Mount Point:              /Volumes/Macintosh HD

   Partition Type:           41504653-0000-11AA-AA11-00306543ECAC
   File System Personality:  APFS
   Type (Bundle):            apfs
   Name (User Visible):      APFS
   Owners:                   Disabled

   OS Can Be Installed:      No
   Booter Disk:              disk1s2
   Recovery Disk:            disk1s3
   Media Type:               Generic
   Protocol:                 PCI-Express
   SMART Status:             Not Supported
   Volume UUID:              0FF5AACE-E455-36E2-9940-5C536F1E3D7E
   Disk / Partition UUID:    0FF5AACE-E455-36E2-9940-5C536F1E3D7E

   Disk Size:                121.0 GB (121018208256 Bytes) (exactly 236363688 512-Byte-Units)
   Device Block Size:        4096 Bytes

   Volume Total Space:       121.0 GB (121018208256 Bytes) (exactly 236363688 512-Byte-Units)
   Volume Used Space:        100.0 GB (100016209920 Bytes) (exactly 195344160 512-Byte-Units) (82.6%)
   Volume Free Space:        21.0 GB (21001998336 Bytes) (exactly 41019528 512-Byte-Units) (17.4%)
   Allocation Block Size:    4096 Bytes

   Read-Only Media:          Yes
   Read-Only Volume:         Yes

   Device Location:          Internal
   Removable Media:          Fixed

   Solid State:              Yes
   Hardware AES Support:     No

Attempt to erase:

steves-MacBook-Air:~ sjs$ diskutil eraseVolume APFS Untitled disk1s1
Started erase
Preparing to erase APFS Volume content
Checking mount state
Erasing APFS Volume disk1s1 by deleting and re-adding
Deleting APFS Volume from its APFS Container
Unmounting disk1s1
Deleting Volume
[ \ 0%..10%..20%..30%..40%..50%.......................... ]
diskutil: diskmanagementd (Disk Management daemon) failure

And attempt to verify:

steves-MacBook-Air:~ sjs$ diskutil verifyVolume disk1
Started file system verification on disk1
Verifying storage system
Performing fsck_apfs -n -x /dev/disk0s2
Checking volume
Checking the container superblock
Checking the EFI jumpstart record
Checking the space manager
Checking the object map
Checking the APFS volume superblock
Checking the object map
Checking the fsroot tree
error: (oid 0xa007) apfs_root: btn: dev_read(500805, 1): Device error
fsroot tree is invalid
The volume /dev/disk0s2 could not be verified completely
Storage system check exit code is 0
Finished file system verification on disk1