1. Tether manipulation of Bitcoin https://coinlib.io/coin/BTC/Bitcoin refer to the Money flow diagram. There are plenty of other HN stories on the Tether situation
Even then this is a strawman, the main use for BTC is not transactions, it is the store of value in front of inflation. Suppose 90% of users saved in BTC and only cashed out once a year, and 10% are frequently using drug dealers (pun intended) that would be a low number of legitimate transactions but BTC itself would be legitimately helping a lot of people.
The main use is speculation not a store of value.
If BTC would counter inflation and keep its value (equal purchase power) even with high volatility no one would care about it. It would still be worth single digit dollar or more likely it would have died a few years after it went online.
People buy BTC because they want to sell for significant more to a later time.
There are two 800lb gorillas in the room though
1. Tether manipulation of Bitcoin https://coinlib.io/coin/BTC/Bitcoin refer to the Money flow diagram. There are plenty of other HN stories on the Tether situation
2. How long will the US dollar remain as the world's reserve currency? For context, https://www.principles.com/the-changing-world-order/ This is probably a big reason for this announcement.