Maybe someone uses bitcoin for money laundering, but I do not think many of them are doing this.
The case of money laundering with bitcoin is real, fiat money exchanged with bitcoin is then transferred abroad, without being detected because of anonymous bitcoin. Unlike fiat money, gold or physical objects that will be difficult when they have to be "washed" or hidden because of illegal activities. Bitcoin factor was rejected by some countries, but this problem must be sought a solution so as not to become a tool of crime.
of course this must be the concern of government, besides having to keep abreast of the times, many governments are not ready to accept BTC for this reason, especially for countries with high corruption rates