The water stopped coming out of the faucet but the hand sprayer still works... I replaced the cartridge but that didn't help. My faucet is an old Moen single lever with a spray attachment.

There is a diverter valve. When you open the spray head the water coming out the sprayer closes the opening to the faucet. Diverter is probably stuck. Replace diverter valve.

Did you remove the aerator from the spout and see if the water ran then? If so then clean the aerator screens, Good luck, Tom