The opposite is true.
As said, the HX711 does not rely on the low 10-bit resolution of the Arduino, and on the stability of the Arduino power supply (which that 0-5volt output of the amplifier does).
With the HX711 you can also forget about the buck converter, and power the Mega (which powers the HX711) with a 5volt cellphone charger connected to the USB socket.
Leo..