Related, a presentation by Raptor Engineering "The World Beyond x86" (video and pdf slides) https://www.raptorengineering.com/TALOS/op_twbx86.php

They delve into x86's freedom and security issues, then discuss the pros and cons of ARM chips versus OpenPOWER chips.

For an open laptop such as Bunnie's Novena, ARM is a fine choice.

For Raptor Engineering's Talos Secure Workstation, OpenPOWER was a better fit.