then where is your boot partition? 
Maybe Iām an idiot, and you can boot without it, butā¦ I dont think so, not with grub at leastā¦
[manjaro manjaro]# cd /mnt
[manjaro mnt]# ls
bin desktopfs-pkgs.txt etc lib mnt proc rootfs-pkgs.txt sbin srv tmp var
boot dev home lib64 opt root run snap sys usr
This is mounting my drive and listing directories. I do not have a boot partition I have a boot directory, as far as i know it has always been like this on my rig including when it was working.
This is more info than I have, I was sure you need a fat32 file system to be able to boot with grub.
Sorry, canāt help then if you say you have never had one.
My file system type is Btrfs.
That explains a few things in your logs when trying to chroot.
But if you insist you never had a boot, I wont argue and wish you good luck!