Currently, Apple has an ASR bug that is preventing system files from being copied. Carbon Copy Cloner as well as all the other backup utils are currently unable to create bootable backups (last 3 OS's) on Silicon machines until Apple fixes the problem. Apple says they will fix it for now but it will probably be removed again permanently in the future, further locking things down!
From Mike Bombich's Blog:
Apple Software Restore isn't quite ready for the new Apple Silicon Mac storage
When Apple introduced Apple Silicon Macs, we discovered another snag. The "Apple Fabric" storage in these Macs offers per-file encryption keys (like the storage in iOS devices), and for months, ASR didn't work with it. Apple partially resolved that in macOS 11.3, but even now using ASR to clone the system back to the internal storage of these Macs doesn't quite work – it causes a kernel panic.
Back in December I had a conference call with Apple about the reliability and functionality of ASR on macOS and regarding Apple Silicon Macs in particular. They indicated that they were working to resolve the ASR/Apple Fabric issue, but they made it very clear that copying macOS system files was not something that would be supportable in the future. Many of us in the Mac community could see that this was the direction Apple was moving, and now we finally have confirmation. Especially since the introduction of APFS, Apple has been moving towards a lockdown of macOS system files, sacrificing some convenience for increased security.
An Apple Silicon Mac won't boot if the internal storage has failed
If you were making your backups bootable in case of hardware failure, then that's an extra logistical chore that you can now retire from your backup strategy.
What did come as a surprise, however, was a very subtle logistical change noted in a
Product Security document published in February(link is external) regarding the new Apple Silicon Macs. A footnote at the very end of the document notes that, regardless of where the boot device is physically located, the boot process is always facilitated by a volume on the internal storage. The lightweight operating system on that volume ("iBoot") evaluates the integrity of the boot assets and authenticates the OS on that external device, then proceeds with the boot process from that external device. What does all of that mean? In
theory it means that Apple Silicon Macs cannot boot at all if the internal storage fails. Lacking a Mac whose internal storage I was willing to damage to prove this, I contacted the authoritative experts within Apple in April and they unambiguously confirmed that that is the actual result – you can't boot an Apple Silicon Mac if the internal storage has died.
Apple has made clear that they will continue to support "external boot" on Apple Silicon Macs, but the reality is that it will be more limited in what it can do. If you were making your backups bootable in case of hardware failure, then that's an extra logistical chore that you can now retire from your backup strategy.