Well, do we need it? Because, I can see that people use it only as an investment or as a money laundering tool. Black markets rebornt after the creation of bitcoin. I tried to convince someone to use it, but you know what? I couldn't. Why? Well, honest people don't afraid the central authority, in addition with the dishonest ones. Those who want something that is illegal, cannot do that. So they use bitcoin.
Here's the thing, bitcoin is not actually anonymous for people to actually hide themselves from the world. Remember how Silk Road was taken down despite their usage of Bitcoin? They are reborn? Silk Road 2.0 and 3.0 was taken down too.
There are more anonymous crypto currencies than bitcoin so I don't think we should always talk about people wanting to use it to cover their tracks, still, do we need it? The question here should be do we want it? Not all of the countries adopted this crypto and despite you having a lot of it, you can't still use it. Anonimity? Volatility? Illegal? Do you still want it? It depends, since as you said, they look at it as an investment.
In terms of Money Laundering,
this article described it as "sparse". Which we can conclude people treat Bitcoin more of an investment rather than a money laundering tool.
Governments don't want it and they wish they could prevent it, because they cannot track you easily, they cannot tax you, they ..., they ..., they...
Governments like censorship, and there is 0% censorship on bitcoin.
I like bitcoin, a lot. But I don't think that this world needs it. Except if they want to hide something. Prove me wrong.
I respect your opinion but doesn't mean people using decentralized currencies means they want to hide something, can't I just have a crypto for investing? It is not always the anonimity that we take account into, it is the profit. Just look how it move in the pandemic, with the right decisions we could earn a lot by taking that dump as an advantage.
Another thing is that not all of the people even want it. In our country not even quarter of our population are using bitcoin. The government have their hands full with more important problems than thinking how they would tax bitcoin since if they wanted to they can just take it all off on exchanges, but they didn't.
Government wanted censorship, that is why there would come a time where people might use crypto currencies not just for anonimity, but for their freedom.