You get cryptocurrency, you spend cryptocurrency, you're anonymous. The person you bought something from, if they want cash instead of cryptocurrency, isn't anonymous.

Or they exchange their cryptocurrency for cash in some place or context without KYC rules. The seller could be anywhere in the world.

Immutable public ledgers, despite their widespread use for online drug markets, are not famous for their anonymizing properties.

The IRS is likewise not famous for its laxity with tax fraud.

> Immutable public ledgers, despite their widespread use for online drug markets, are not famous for their anonymizing properties.

You know that some public key had some amount of cryptocurrency and then it went somewhere else, possibly into a cryptocurrency tumbler. You don't know the identity of the person holding it and as soon as they have enough to buy something they can stop using that now-empty wallet.

Also, Monero solves this more robustly, doesn't it?

> The IRS is likewise not famous for its laxity with tax fraud.

Who said anything about tax fraud? You can report the income on your tax return without specifying how you spent the money.

How do you think it works with physical cash? The advantage here is that it can happen over the internet.