Voltage drop from a logic gate?
A real gate would not be able to supply anything like 455mA. You've loaded the output with far too low a resistance. Try something more like 100K or 10K.

They've probably added a placeholder 10\$\Omega\$ resistance internally just to prevent infinite current if you short the output in the simulation. A real gate would be more like 100\$\Omega\$ (though it does not behave exactly like a constant value resistor when the output voltage drop gets higher than a fraction of a volt).