Isn’t that the purpose of money laundering, to create an income stream so that you can pay taxes on it? I don’t know tax law in depth, but it seems like if one could just report to the IRS anonymous money it would largely obviate the need for money laundering at all. Of course there’s the question of other gov agencies.
You can always cash out "Bitcoin you [allegedly] bought back in 2010", or Monero you mined back in the day so there's no way to even prove its source, and declare that to the IRS. With a cost basis of almost zero, you'll pay long term capital gains tax, 15% or 20%.
BTW when you declare your crypto gains, the IRS not only does not care about the source, there's not even a place on the forms to list the source.
