The advantage of this is that it might subsume other redistributory policies. A lot of money is simply transfered from one person to another in this country, and to have a single method of doing so would make every adjustment to the amount a large national debate, rather than a rider on a bill no one reads.
It would also make the benefit impossible to kill or reduce no matter how much it strangled the nation. See: Social Security.
The difference is that instead of the AARP threatening nuclear warfare over any reform it would be everyone. (Incidentally, if you think the AARP is going to give up Social Security just because they're getting Basic Income in return, you're dreaming.)
