For those who don't know, -and this is more of the result of the EFI Boot partition scheme- before that, for MBR systems ,one can use Veracrypt to encrypt the entire System Drive - and this allowed a unique option that I have not seen anything else ever able to replicate- it enables an option that lets one hide an entire OS-
The Hidden OS option is restricted to legacy boot mode- and that's being more and more dissuaded in general- So i fear the airtightness of the Hidden-OS capability will no longer be reachable for consumers.
I had seen one effort on it - https://portswigger.net/daily-swig/russian-doll-steganograph...
and https://i.blackhat.com/eu-18/Thu-Dec-6/eu-18-Schaub-Perfectl...
However, I have since then not seen anything on this sort of capability- and no other encryption software has focused on steganography and encryption/plausible deniability capabilities to this level.