Because Amazon opened up the development of Alexa Skills to anyone with the free Alexa Skills Kit (ASK) in 2015, anyone can create an Alexa Skill. As Alexa uses Natural Language Programing (NLP), those looking to build a skill don't need to worry about complex speech recognition. The ASK tools also makes it easier for novices to work with sophisticated NLP ideas.
Amazon's Alexa-powered speakers are great for a lot of things beyond playing music or changing the color of your smart bulbs. Alexa can play audiobooks or read your Kindle books to you, if you don't have the audiobook version. It can give you the forecast, the latest tech news (with CNET!) or tell you if you should expect traffic on your way to work. And it can, of course, tell you a few jokes.
Like all AI devices that use National Language Processing or NLP, Alexa does not understand all voices easily. But she learns to understand her people over time. She does, however, require people to speak in simple terms, with appropriate pauses, and use specific word orders. There are many times when she will say "I'm sorry, I don't know the answer to that question." More than likely, she doesn't recognize a word order or misunderstood the question.