AES can only encrypt up to 64TB; after that you need to re-key. So you need a mechanism for rekeying anyway. Definitely a good idea to use a battle-tested tool like wireguard instead of rolling your own.
I think alphager is referring to the upper limits of AES before a birthday attack becomes a concern. In GCM mode there's a realistic chance of an IV being reused after around 64GB of data. Other modes have differing limits.
Truly. I think IPSec is practically more "battle tested" than wireguard ever could be, and IPSec offers more useful functionality than wireguard ever will.
