Or just pay state taxes and the state allocates some of their taxation to the feds from there.

This gives bonus incentive for state governments to monitor how much they spend on the federal government, as well, as spending too much would be money lost to them. Of course the incentives extended aren't perfect, but at the least it turns the accountability onto a lower level and more spread out. Instead of just needing to bribe 100 Senators and 435 House reps to control the nation, they'd need to bribe the state senates/house of each state. Sort of like 50x the number of officials, although of course the actual math is a lot more complicated.

But yeah largely cutting federal size astronomically. Some programs might remain out of general utility and being relatively benign but most of the authority really can be transferred to the states. That becomes a proper situation of taxation WITH representation instead of ~600 people deciding how many shits a day an entire country of over 200 million can take.