Actually, Chromebooks should be the most secure laptop platform nowadays, since every Chromebook has signed binaries and to enter in developer mode, you need some kind of switch so you can overwrite your bootloader.

Of course, this is assuming Chromebooks' bootloader doesn't have any secured problems.

Assuming that the signing key hasn't been compromised and added to an attacker's collection of keys, which is something certain three letter agencies have a habit of doing.