I feel the tax reason is only one side of this. Governments are looking at ways to tax crypto, and from what I can tell in most cases it is being treated in the same way any other asset/investment is treated with a CGT component.

On top of this, some governments have already looked at taskforce/investigate help to be able to identify citizens invested in crypto, and a lot of this already exists for the typical cases of keeping an eye on money laundering etc

I get the feeling, and there is a small amount of tin-foil hat to be worn here, that there are some larger players and 'powers' that also tend to force the hands of governments a little, either to get ahead of crypto for their own gain, or to stop any further decay of power via decentralization (or fear of it).

There is actually a great book about this decay of power called "The End of Power" which I think people should check out that does a much better job illustrating this idea.