>You misunderstand: That IS the internet.
It's really not. There are dozens of protocols for network addressing and when the internet actually became big the IP had long ceased to be anywhere near the best one. It was archaic long before the internet spread off university campusses.
The internet's success came from the lack of government or corporate control - not from the technology, there were more advanced large scale networks before anybody outside academia had ever even heard of the internet. It displaced them due to lack of owners - not because of the technology. Cerf himself has said there are things he would do differently if he could do it over now. Many of which he wanted to do even then but the machines which arpanet ran on at the time (mostly PDP10's) simply didn't have the processing power to handle (like built-in by-default encryption).
Anyway, IP is not even the lowest level protocol on the internet. What about the routing protocols ? What about the hardware protocols ? Those had improved over the years and, in fact, have proven to be better for a true internet BECAUSE they were easy to swap out.
We are tied to IP only because of the cost of changing, not because it's the best available tool for the job - hell we can't get the world to even adopt the best available version of IP.
You overstate and greatly overestimate the important of IP to the internet. If one of the other early large networks with more advanced address protocols had offered the lack of either government or corporate control the early internet had - the internet would have died out before the 1990s even hit. As late as 1991 most computer scientists were convinced an information superhighway was coming and convinced it would not be the internet which was an archaic piece of technology that was simply nowhere near the best we had.
The one thing they hadn't counted on was the attraction of a lack of centralized authority.
So removing one of the last vestiges of centralized authority can only strengthen the internet's sole good attribute.