Oof, yeah, those vibes are rancid. The website is covered in shady looking links and they want you to download an exe, which you don't need for a simple registry edit which can be done with a text file.

This link shows you how to make the .reg file: https://www.windowscentral.com/how-take-ownership-files-using-right-click-context-menu-windows-10

For my money that's way easier than doing it manually through the registry editor yourself, and you can inspect the code to see what it's doing.

If you want to see the manual steps to take ownership without the registry entry, it looks like this: https://www.windowscentral.com/how-take-ownership-files-and-folders-windows-10

If that isn't a dark pattern then I don't know what is. They do not want you to have control over your machine, at all.