People who file Form 1040NR (as nonresidents of the United States) will sometimes receive a tax refund. Sometimes it is large, sometimes it is small.
The IRS, by default, issues a paper check for refunds.
It will shock you to discover that sometimes paper checks take a long time to reach their overseas destination. Sometimes the paper checks never arrive. Or sometimes it is a big hassle to deposit the U.S. dollar denominated check into a bank account overseas. Or it costs a significant amount in bank fees to get this done.
In short, paper checks are an abomination.