[psanford]

IPSEC without IKE is not "similar to how wireguard works actually." Wireguard does actual key exchange and has security properties such as Forward Secrecy that you don't get using a hardcoded IPSEC symmetric key.

Also, even the IPSEC config without IKE is way more complicated than a Wireguard config, with seriously sharp edges. Just look at that config you linked to. No one should ever need to know what AH and ESP are, but if you don't you very easily can configure IPSEC in an insecure manner.