Paraphrasing the Nielsen Norman Group, voice assistants suck. Amazon Alexa, Google Assistant, Siri and, I am guessing, Cortana.
Of course, the level of suck depends on your mastery of English accents, so I expect they suck more for Danes than for white middle class Californians. Just guessing here, of course.
Voice assistants are the latest attempt at a zero-cost interaction system, and so far it has failed.
For example, when asked for a recipe, Alexa provided a “top recipe” with the option for more. But it gave no information about what “top” meant and how the recipes were selected and ordered. Were these highly rated recipes? Recipes published by a reputed blog or cooking website? People had to trust the selections and ordering that Alexa made for them, without any supporting evidence in the form of ratings or number of reviews. Especially with Alexa, where users could not see the results and just listened to a list, the issue of how the list was assembled was important to several users.
However, even phone-based assistants elicited trust issues, even though they could use the screen for supporting evidence. For example, in one of the tasks, users asked Siri to find restaurants along the way to Moss Beach. Siri did return a list of restaurants with corresponding Yelp ratings (seemingly having answered the query), but there was no map to show that the restaurants did indeed satisfy the criterion specified by the user. Accessing the map with all the restaurants was also tedious: one had to pick a restaurant and click on its map; that map showed all the restaurants selected by Siri.
— Raluca Budiu and Page Laubheimer/Nielsen Norman Group, “Intelligent Assistants Have Poor Usability: A User Study of Alexa, Google Assistant, and Siri“