Some here are mixing bootloader unlocking with rooting. They're not the same thing.
Asus broke bootloader unlocking, so you can only use the original ROM in the original state. You can't install a custom ROM or flash something like Magisk to root your device.
You can unlock without rooting or without installing a custom ROM. You can install a custom ROM without rooting. You can use stock and root. And you can use a custom ROM and root. But all this is only possible if you can unlock the device's bootloader.