I don't really have a strong opinion on whether they are or aren't, nor a desire to get a definitive answer. What I've realized though is that these "products" like alexa and google home exist solely for the benefit of Amazon, Google et al, as data collection devices (irrespective of whether they eavesdrop outside of activation). They are not useful to me (alexa favouring some stupid Amazon music over my connected spotify account was the death knell) and I don't see a reason to give these companies another window into my life, even if they do it within their TOS, so I don't use them. Whether or not they are actually eavesdropping for some definition is not worth thinking to hard about