Installing apps in Windows is a privileged process. This keeps the average user from corrupting a system.
The only users that can install apps are ones with Install Apps permission (I forget what it's actually called). Anyone in the Admin group has this. The group Users does not.
In a business/domain environment, very few people get local admin rights. For a home user best practice would be to run as a User or at most Power User, and only do admin level stuff when logged in as an Admin.
No one does this, of course. (I certainly don't, even though I know better. It's just easier to not do risky things and maintain backups).


