theres nothing btc can do that cash cant in terms of illegal use.
That's not entirely true: almost all ransomware gangs will only accept crypto payments, not cash.
The problem with cryptocurrencies is not their moderate superiority over cash for illegal use (and I agree that none of the crimes they enable are
novel), but their massive inferiority compared with cash (including electronic transfer, not just the paper notes) for legal use.
Probably nearer to a Truck currency seeing as you can only spend them in the company store.
One thing that both real currencies and pseudo-currencies like book tokens, gift vouchers, postage stamps, company dollars, etc. usually have which ARX doesn't is the ability for the holder to transfer them to someone else, who can then redeem them separately. That gives the pseudo-currencies some value (often close to or at their face value in their base real currency) that ARX doesn't have.
If anything, ARX is probably best viewed as just another in-game asset like credits or materials or exobiology discoveries. That you can increase your amount of ARX by giving Frontier cash directly doesn't make it any sort of currency itself. (Obviously ARX and Credits - but not materials or exobiology discoveries - use a currency-like metaphor inside the game for convenience of player understanding, but that doesn't make them currencies from an out-of-game perspective)
