Because last time (15 years ago) I used Migration Assistan. it doesn't migrate the root folder and preferences files but only the ~/ (your user directory), so it was a paint to rewrite everything like Serial Numbers of the apps, preferences file etc...
But this time, Migration Assistant is improved! I've done the "clone" with it and it has worked very well, I still have to test some PGP keys and Homebrew apps but the apps like i.e. Adobe suite has been migrated frictionless. Very happy with it!
Plus I have some auto-login apps that are not ARM ready, and MA has copied all of them but they aren't auto-opened at the login, you have to confirm that you want to install and run Rosetta (to recompile them).
Very smart behavior! Kudos to Apple this time.
I still need to make a bootable Carbon Copy Cloner disk but I'll investigate in it in the next days, the trouble now, is that I cant' make a common/doyble with my iMac and MacBook M1 with the option to clone "update only the modified files" because one installation will not work on the other architecture, plus, if I open an Intel app with Rosetta it should delete the x86 files, so, make a clone it very dangerous because if I'll need to boot my intel iMac from this clone, I'm pretty sure will be impossible or some apps will be damaged!
But I can wait for the arm iMac ?