Why can't I return the smart speaker when it's activated

At the bottom of the product display page is the word "no return if the smart speaker is activated". And the meaning of returning and exchanging goods without reason within 7 days means that within 7 days after signing, without affecting the secondary sales of goods, you can return goods directly without any reason, which does not mean that you can return goods casually within 7 days. Now the situation is: the unpacking is activated, and non quality problems do not support the return and exchange of goods. The merchant sends a good product to the buyer, and the buyer has used it after activation. All, there is no quality problem, there is no reason to return. The returned goods belong to second-hand products. There is a problem of depreciation among them, which will lead to depreciation fees. Who should bear this cost when returning goods? Therefore, this is the reason why the smart speaker cannot be returned when it is activated.