I wonder what kind of new internet will emerge from the ashes of everything we've been using since the 1970s, when it finally all goes up in flames in the next few years.
I think you underestimate the sheer tenacity of crappy solutions.
I think you underestimate how badly things are failing.
You'll need a really, really, really massive meltdown before people are willing to fork over the money necessary to restart from scratch. Not even nuclear meltdowns have historically convinced people to do that. Not even global warming is convincing people to do that.
Do tell, how badly are things failing?
Do you have data besides "look at all the vulns!"?
Do you have clear evidence of a negative economic trend that is linked to insecure software?