Federal courts generally aren’t overloaded the way state courts are, and federal prisons generally aren’t overcrowded the way state prisons are. But if theft of less than $1000 in property became a federal crime that would certainly increase the number of federal cases and federal prisoners.

There’s also a question of how to shoehorn smaller theft into a federal crime. It can be done — any bank robbery is a federal crime regardless of how much money is stolen — but it isn’t straightforward.