Okay, how is it that we destroy the economy by boycotting a brand and driving them into the ground IF the following is true?

Bud Light boycotters don't stop drinking beer; they just stop drinking Bud Light. They still spend their beer money on beer; they just spend it somewhere else.

Same with Target. People don't stop buying the stuff they usually got at Target; they just buy it somewhere else. (Though admittedly we're running low on places to buy stuff. Fortunately, many of us don't need much stuff nowadays. But I feel for people with small children who need diapers and kids clothes that are being grown out of and other such stuff.)