The Diamond Age is based in a reality where all countries collapsed due to the advent of cryptocurrency and cryptocommunication which undermined nation states' ability to collect tax. I think this is an eventuality.
One of my favorite books, but the chicken and egg problem is substantial. Hitting the "tax dodger" tipping point requires a huge number of people to break the law before it 1) has any impact at all, and 2) becomes unenforcable.
Nations are not based only on the ability to collect tax. And a percentage of income or sales are not the only kinds of tax which have been collected in history.
The Diamond Age is also a sickening crapsack world filled with immensely dangerous uncontrolled nanotechnology. And of course the mandatory Neal Stephenson lectures on programming and bizarre sex cults.
That said, Snow Crash was an even worse crapsack to live in.
