Question: Features like port sec and DHCP rate limiting are implemented to prevent DOS attacks like DHCP Starvation and MAC Flooding. The solutions usually involves the device to shutdown the port or drop further incoming packets. Isn't this what the attacker wants to achieve?

I am a networking student with CCNA R&S and 0 networking working experience. I know that I am definitely missing out on something, please help me fill in the gap.