Just because bitcoin is anonymous does not mean that transactions cannot be traced.
The great utility that bitcoin has is that all its operations can be tracked, there is an " * "here with that, but saving that, it is more difficult to wash bitcoin than the traditional one (Fiat), it is a technical issue that compares technologies and it is something not complex but extensive to explain, but to understand it more you should read about the AML laws and how Fiat money evades them, mainly with the use of tangible money (paper money) and that is the big difference for example with the use of bitcoin, It is electronic, it is 100% auditable (minus the exceptions that arise with "*").
Fiat money coexists between physical money and electronic money and although with certain tricks electronic money may not be 100% auditable it can be traced, but when converting it into paper money, its use is practically private and depending on the skill of the person who uses it, can make it anonymous.
If you are still lost on the subject, to finish I can tell you that each bill (paper money) has a unique serial but only serves to identify its end user (e.g.) but it does not describe in which transactions was he involved or by what "hands" this money was used on its existence; with each satoshi that exists you can know its life line in each transaction.
Sometimes you have to understand related topics, to understand certain questions or concerns, it is an interesting topic that involves things like AML, KYC, among other topics.
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