The original power supply has an output of 5.2 V / 2.4 A and the part is marked with 64W. With a USB 3.1 USB-A/USB-C cable with 30 V (without A specification), I cannot charge it from the mentioned QuickCharge from Aukey, but I can from the PowerBank from Aukey with the original USB-C/USB-C cable. The QuickCharger and PowerBank have the same specifications. So it may well be due to the max. 2 A?

A maximum of 2 A is specified for this cable.
What does the MacBook need to charge?

Other cables can handle up to 4.5 A, for example.
I don't know the MacBook, but I think that 2 A might not be enough.