Unfortunately from Apple's perspective that all makes sense. Why clone the System when you can do an Internet Restore and grab the System from on line. Well, I can still think of reasons—like no Internet connection—but Apple does not ask me.
Don't forget that if your Mac has a T2 chip, as I believe all new Macs do, the T2 chip prevents booting from an external drive unless you boot from the recovery drive or internet recovery drive and disable that feature, so internet may still be a requirement, even if you have a "bootable clone". By-the-way, I can tell you from experience, that also prevents booting from a Recovery Drive on any device other than the internal drive.
I have a late 2018 Mac Mini, and it has a T2 chip. I can boot it from an external SSD containing a SuperDuper! backup/clone. I did not do anything in terms of disabling a feature. (I am running the latest version of Catalina, OS 10.15.7).
