There’s nothing magic about Soylent for weight loss. It’s a simple equation of calories in and calories out. The advantages that Soylent offered me was convenience for counting said calories, convenience for meal prep, and being reasonably certain my body was getting a decent distribution of micronutrients
RE: backups, I’d recommend altering your workflow. Instead of taking an image of a box, automate the creation of that box. Create a bash script that takes a base OS, and installs everything you use fresh. Then have it apply configuration files where appropriate, and lastly figure out which applications really need backup blobs to work properly (thunderbird, for example). Once you have that, your backups become just the data itself. Photos, documents, etc. Everything else is effectively ephemeral because it can be reproduced through automation.
Takes a lot less space, is a lot more portable. And much better in scenarios where something in your OS is broken or you get a new computer and want to replicate your setup.