A good practical use of the Tags feature is sharing files with other users. If a set of users are tagged e.g. 'Alpaka Staff' then you can use the Share Files With Team feature and share files with those users based on filtering/grouping them by using the tag.
In your navigation > FILES and choose to edit the file by clicking on the pencil icon and click on the 'Share with Team' button.
In this example I have chosen to filter to 'Send to users with these tags'. When clicking 'Submit', that file you are sending will only be shared with people who are tagged 'Alpaka Staff'.