What's a megaproject you know is probably a bad idea, but would be sorely tempted to try if you were the leader of a wealthy country?

Vending machine economy.

Turn stores into giant vending machines. Turn restaurants into automats. Public vending machines with basic human things in them like toilet paper, instant coffee, OTC medicines, first aid, etc. We would create virtually indestructible vending machines and mechanisms. Vending machines and the products inside would use local branding. You would also have exclusive treats that reflect a local culture. Also, no currency to use them, just biometrics.