Are you even talking about GNU/Linux? Most of the comments in this thread have been about MacOS and Windows, and I made no claim regarding those. FDE with LUK

Are you even talking about GNU/Linux? Most of the comments in this thread have been about MacOS and Windows, and I made no claim regarding those. FDE with LUKS/dmcrypt has been an out-of-box installer-supported mode in all the major distros for a long time now.