Yes. As soon as you start with the "well no you don't qualify for the 10K because, fill in the blank. You then need hoards of bureaucrats to determine eligibility and all the other bull crap.
The only requirements should be that you are a citizen of the United States and that you are of age (18) to receive the payment. If you make it so each child gets a check, the explosion of "check babies" by the gibsmedats would crush the system immediately.
The whole concept disappears up its own butt when viewed on those terms.
To phase it out would, as Mad Dawgg sayes, require hoards of bureaucrats.
And probably cost more to operate than the system is was replacing... *Place idea in round filing cabinet in corner of room*
I also think this would also result in massive levels of identity theft and fraud. And it would be “racist” or something similar to investigate or punish it.