Honestly, that was my impression at first. But the difference (in hindsight I've never really looked into other apps) is that they actually list ALL files they flag for removal (In Gemini 2 as well) so you do have the option to double check what the app does. You could even let it run in trial (500MB deletion limit) and then plainly look at the list and go delete it manually.

The apps are also not "mass produced", they have really nice animations and you can definitely feel that there has been a lot of effort put into them.

They also make some music player and encryption apps so they're not all cleaning apps.