I'll never have another credit card. Frequent flyer miles, what are those? The whole industry can go fuck themselves.
If you pay it off every month, credit cards have a negative cost (to you) and a fair amount of convenience (for renting cars, hotels, booking flights, etc).
Nobody cares about your data (unless you're high profile), but -- for example -- hedge funds and the like will spend big bucks to get aggregate sales data before this quarter's financial reports are written.
Sometimes you have to identify your weakness and ruthlessly cut them out of your life.