That's correct for dd but not for clonezilla.
Clonezilla uses partclone, which reads the file system and copies only the data, for any filesystem sorted by partclone.

Source: Many File systems are supported: (1) ext2, ext3, ext4, reiserfs, reiser4, xfs, jfs, btrfs, f2fs and nilfs2 of GNU/Linux, (2) FAT12, FAT16, FAT32, exFAT and NTFS of MS Windows, (3) HFS+ and APFS of Mac OS, (4) UFS of FreeBSD, NetBSD, and OpenBSD, (5) minix of Minix, and (6) VMFS3 and VMFS5 of VMWare ESX. Therefore you can clone GNU/Linux, MS windows, Intel-based Mac OS, FreeBSD, NetBSD, OpenBSD, Minix, VMWare ESX and Chrome OS/Chromium OS, no matter it's 32-bit (x86) or 64-bit (x86-64) OS. For these file systems, only used blocks in partition are saved and restored by Partclone. For unsupported file system, sector-to-sector copy is done by dd in Clonezilla.

The easiest way to solve this kind of issue on Nixos is to add

environment.systemPackages = with pkgs; [ steam-run ];

to your configuration.nix, rebuild your system and then run the binary with steam-run, like steam-run linuxrulzgame

Well said! I'm in complete agreement.