scant poster, long time lurker here, OP is right.
i've thought about this myself over the past few years.

he's not talking about current systems. so the whole example of registering a car in NM is barely a counter-point.

instead... imagine a not too distant future, where you had to use btc or some other digital currency. and every wallet is registered, like a social security#.
perhaps you want to buy a car from a friend. you both agree 5000. taxes due.

today, you can give him 5000 cash and register paperwork for sale of 100. taxes on 100.
future, "they" (governments/banks/irs, etc) will detect transfer of 5000. all taxes due.

what about work under the table or "off the books", for cash? today its possible. future... nevermore. with digital currency, blockchains everywhere, on everything and a mandatory wallet thats registered to you? Doubtful.

remember, if you've ever bought bitcoin using a marketplace (coinbase, bitstamp, bitfinex, etc, etc) they know who you are and what youre holding. all the feds have to do is ask and those companies are usually all too happy to comply.

"well then, i'll move the coins from my Bitstamp wallet to a new wallet and they'll never know"

no. they have blockchain analysis, clustering analysis for this. and companies like coinbase in the US are already required to us it us it to comply with KYC/AML (know your customer / antimoney laundering) banking laws.

anyway, its a bit troubling when you think about it. ironic too. people (or a person) started this whole thing, and it could be our entire undoing.