It’s a federal matter because a state asked for their assistance as they can’t go out of state to arrest them.
Your argument is much like states saying illegal immigration is a Federal issue so the state can’t help them one bit.
“It’s a federal matter because a state asked for their assistance as they can’t go out of state to arrest them.”
Your reasoning is flawed. States can ask whatever they want but unlike immigration violations, there is no federal offense at stake.
The compacts clause and the "full faith and credit" clause were meant to control how states interact with each other, with Congressional oversight.
That's not what Illinois is doing to Texas. Illinois is supporting a dissident minority faction to obstruct the lawful government of another state.
-PJ