Bitcoin will never become big enough to render fiat obsolete. But they are right about the fact that once bitcoin is off the grid, it is very difficult to pinpoint the location of the money. It is why bitcoin became popular in the first place, and why governments are trying their best to control it.
I'm beginning to think they are playing dumb. There are actually treasure troves of deanonymization tools available to governments which have been developed by Chainalysis and their competitors for years. They've got databases full of metadata like bloom filters, leaked tracker information and PII data, IP address data. For all we know, companies like Bitpay or other merchants are honeypots to identify our wallets via address clustering.
They're watching us and the problem is only going to get worse. If you think Bitcoin is "private" by default, then read this: arxiv.org/pdf/1708.04748.pdf
The U.S. government just wants to spy on its OWN citizens
and try to find a way to double tax income!
This guy's got the right idea. Bitcoin is incredibly transparent and trackable. That fact, combined with the pernicious use of third party trackers and lack of care with IP address privacy means that Bitcoin is serving a lot of our data to the government on a platter.
It's time to get smart, learn how to make your funds un-linkable, encrypt all communications, use TOR and I2P, get off the grid......