Earlier quoted context omitted.
No practical purpose EXCEPT for the ability to easily take assets across borders to leave authoritarian regimes, bringing a form of storing assets to the 2 billion or so unbanked individuals of the world, and comparatively cheap remittances for people sending money back to their families in another country. These are just a few of the incredibly practical use cases that quite literally change people's lives.
All of those things that make it easy to move money out of authoritarian regimes also make it easy to move money into them - see the recent North Korea hack. Turns out that when you purposefully build a system without any guardrails or oversight, then bad actors will find exploits and there will be no way to stop them. Regulation and oversight might be good things, actually.
The "exploits" you're describing were possible 20 years ago through various other methods (unregulated banking, cash in briefcases, etc). The new thing is government and police having a much greater degree of control over monetary systems.
I think crypto is failing at most of its promises and it's still unclear whether it will ever live up to any of them. But rah-rah celebration of government being able to monitor and halt anything it wants to is not the way to go, either; it's actually a literal doomsday scenario (Vernor Vinge has written about this, among others).