Are you talking about High Sierra, or iOS devices? Because this just isn't true about my macbook pro running Sierra. There is no granular permissions model as in, for instance, Android 7. I give my (super) user password to install apps on my mac, and then after that, they run. There's no further permissions I can or can't grant, and there's no way to run install many desktop apps without my (super) user password.
Edit: It seems you a many of the others replying to the GP are talking about apps from the App Store, which I basically never use. And that's sort of the parent's point, I think. I get apps from the internet, install them, and use them, like and old-school desktop/PC computer user. I rarely need to use the app store (except for updates, and it's weird UX that OS updates are in the app store to begin with) and have no compelling reason to do so.