I live in Japan, where most transactions still are cash oddly.

I normally pay my rent in cash like most people, so I would obviously pay my rent in cash.

Plenty of tourists and rich folk here in Tokyo who spend crazy amounts on food, so I would eat like a king.

Rich people tend to buy expensive watches and bags to younger girls or guys, so I would buy and resell some expensive branding at those stores. There's plenty of hypebeasts and brand re-sellers here also, so regular re-selling of hype-brands also. Electronics are re-sold here also at a large scale, so I would just buy electronics at smaller stores and re-sell them.

Cryptocurrency is popular here now, with actual billboards and stores offering it, so I would dump some cash into it.

Would def take some time, but eating anything I want and having the option to go on great once in a lifetime trips all the time, without leaving traces on my credit card due to everything being cash would still be nice. You would be surprised how many laws are being broken everyday by regular people and companies here, so I wouldn't worry as much here as, say in the states.