From what I understood, MAC addresses are physical addresses only used in LAN to identify a device.
However, local IP addresses can also identify a device on a local network as it is unique.
So why do we bother to include MAC addresses when we could have only used IP addresses for both LAN and WAN ?
I understand that this is what the OSI model and some protocols are based on but my question is rather why has it been made that way in the first place ? It seems like additional unnecessary data to send through the network and MAC addresses it can be spoofed.
Let me give you a simple answer. THE local IP address will dynamically change when you are disconnected from the WIFI network or ethernet. (sometimes it's not changing because that anyone else is not connected to the network to reserve your recent IP). so MAC address is a unique address for your network card. We can uniquely identify your device from it. It cannot be changed but nowadays also can change it.