Why is the datasheet showing VGS at absolute maximum?
The absolute maximum voltage rating of Vgs for the IRLZ44N is +-10V. Above this rating the device could be damaged

The Vgs threshold for guaranteed to be ON is 2V and the voltage for the device to be guaranteed to be OFF is 1V

Driving this device with 5V Gate-Source potential is perfectly fine and is a good choice to ensure the device is ON