[derleth]

You could if the new machine was very similar to the old one. In practice, the new hardware is better in some ways, so just copying everything will either not work at all or only work sub-optimally.

OTOH, your personal application configuration files (editor, window manager, etc.) can nearly always be copied as-is without causing any problems. Some people have been copying the same .emacs from machine to machine for years, if not decades, upgrading Emacs all the while.