Would using separate user accounts on Linux be a valid method to isolate untrusted applications?

Title pretty much says it all. I want to prevent applications which aren't open source or privacy friendly from snooping through my home directory. If I installed them in a standard user account without using root or my admin password and kept my private files in my admin account, would that work? In my case, I want to install Steam or other gaming platforms on a standard account.

Yes I know about virtual machines but they don't have best performance. …

accounts applications linux privacy untrusted valid