It's a difficult issue. I'm definitely not suggesting we shouldn't attempt boycotting, just that our tactics need to change for modernity. As you said, they are already difficult to accomplish effectively. Even just 50 years ago, you and your whole town stopped buying from Joe's Wares could work. Today, boycotting now that Joe's Wares can make sales online means your town is never getting rid of him, regardless of whether you all never buy from him and actively dissuade others from doing so.
Moreso if Joe's Wares knows they can buy reviews and other scummy tactics to make them look more worthwhile than they are.
That's an interesting snippit, definitely something that feels true to society today still. Similar to how I said is disheartening in how many people are apathetic to a cause, that's a very apt description to what exactly about it becomes so tiring.