Just some guy saying some things
It’s your phone, it’s your app store, it’s your browser, it’s your email, it’s your storage, it’s your search, it’s your maps, it’s your music, it’s your news, it’s your credit card, it’s your password manager
Google is so deeply integrated into most people’s lives that they can’t imagine going without it.
The next line implicates the de.mschae23.grindenchantments mod; seems like a pretty clear starting point for troubleshooting.
Sort your data into stuff you absolutely need to keep (personal files and such) and stuff you’d be okay with losing (less important files, device backups, downloads you can redownload, etc). Then only back up the former. As for backup medium, ServerPartDeals often has some pretty good deals on storage; they were selling refurbished 12TB drives for $80 a pop a while back.
Mint does have a graphical app store. Steam also has a .deb package on their website to download, which opens by default in the GUI installer when you double click it. Using the CLI is fine, but it’s definitely not necessary.