> IP looked at that and said: fuck that noise - we send packets, if they don't arrive we send them again, job done.

The difference between IP and the OSI stack is the standards development organizations: IP was specified in a fairly unofficial way (RFCs) by academics via email in what eventually evolved into the IETF, while OSI was specified by ISO. ISO is much more difficult to work in than the IETF. But there are still specifications behind IP. It's not 'just send a packet and see what happens'.

> Protocol complexity is where bugs hide, including vulnerabilities.

You can't make that go away. TCP/IP is not a non-protocol. The best you can do is minimize that complexity.