A barrage of new gadgets proves that Amazon is so relentless that it will even compete with its best friends (AMZN)

Mark Lennihan/AP Amazon announced a whole bevy of new Alexa-powered hardware on Thursday, including a microwave, a car gadget, and a smart plug. The thing is, though, that some of Amazon's buddies in the world of electronics manufacturing already offer Alexa-integrated devices in all of those categories. This means Amazon is now competing with some of the partners showing it the most support. To be fair to Amazon, the world of smart home appliances is growing fast and far from settled, and the r...