That's a what, not a why.
Why can't USCIS shard it based on country within the US in a similar fashion?
The whole immigration system could easily be reformed and modernized if efficiency and speeding up the legal route to citizenship were the goal.
Because it’s literally not better than the DmV
alt Hacker News
The whole immigration system could easily be reformed and modernized if efficiency and speeding up the legal route to citizenship were the goal.