I get your frustration @rywbl there’s no worse feeling than losing your valuable files. like @rigmarole said, try to see if the files still exist in your computer or in .trash in your obsidian folder (which is a hidden file).
For the future like @rigmarole said you can do a git version control without the need of connecting it to GitHub /GitLab
Although, putting things in a GitHub / GitLab is always a great idea (in case your computer fails), you can even have your project in private. (even if your internet is slow, you can just leave things loading in the background) a slow backup is better than no backup.
I’m not sure if you know this process for git, but it might be useful for you or others, so I’ll put it here.
in the terminal
cd to/your/obsidian/folder
git init
git add .
git commit -m "this is a comment"
then for every back up you can just do
cd to/your/obsidian/folder
git add .
git commit -m "this is a backup comment"
and like @koKekkoh said there’s a way to do all of this from inside Obsidian with this amazing plugin.
I don’t think it’s fair to blame the Obsidian developers, they do a great job and the software is still in beta. Backups are the user’s responsibility.
I understand if your post came off sounding rude without intending to, (English isn’t my first language either so I get you) hope this helps
Good luck!