During Amazon’s Prime Day sale four years ago, I found myself staring at a listing for an Echo Dot smart speaker. It was on sale for half price. I wasn’t browsing with any particular smart home gadgets in mind. It was simply being advertised on the homepage of the e-commerce giant’s website, and I lack the impulse control to resist a good bargain. I purchased it thinking I’d just use it as a fancy voice-controlled radio for my kitchen — much like my parents’ second-gen Echo back…