The answer is YES. you may use Alexa/Echo without needing the cell phone for long periods of time, but eventually it will be rendered useless all in a day, by some update that requires you to interact through that account and the cell connection... I have found no way around this yet. Although I run months and months with no issues, all it takes is one thing to happen and it's FUBAR. Always requiring me to re-establish something in the system through the phone. I have ONE Dot that has issues that are mostly due to distance from my router, that will not always reconnect without me accessing it through the cell app... all others in the house (and 5 tablets) have no problem re-connecting on their own. If I understand correctly, the Contacts are from and attached to the cell phone account as well, somehow.