And depending on where you live you wouldn't be able to make big purchases in cash (in France I think the maximum cash transaction allowed is about 3000€).
BTC or cash you would have to launder your money to make it look like legit and be able to buy a house etc
Of course the other problem of BTC is that transactions are stored forever (as long as the BTC network operates) so it might bite you decades later.
This has to be the worst reason a drug dealer would avoid dealing in cash ever. Inflation is literally 2% per annum. Drug dealers pay 20%-50% to launder their money. C'mon now.
Deposit money to Binance, covert to XMR, withdraw XMR is well under 0.1% total in fees.
There is no such thing as a free lunch.
Yes, there are risks involved in doing criminal business, inflation is not one of them
That thinking is quite shallow.