Even if you're not required to file a tax return, here are the reasons you'd want to file anyway:
- To get your tax withholdings back
- To get refundable credits you qualify for, like the Earned Income Credit, the Child Tax Credit, or the American Opportunity Credit
Otherwise, don't file a return if you don't have any withholdings or qualify for any refundable credits. You don't need to prove to the government that you have no taxable income (they already know), you won't be able to e-file, and if you paper-file you'll just create unnecessary work for them and for you.