Especially in rooms where you don't already have a sound system, it's really a no-brainer. And I question that you've ever interacted with a smartphone if you think either the responsiveness or the convenience (not everybody is glued to their phone, and sometimes it's in the other room).
This need people have to think everything is either super-tubular-amazing or completely-useless-dross is _exhausting_. For anybody interested in understanding instead of posturing online to fill some emotional void, it's plainly obvious how smart speakers could be a modest improvement to QoL for many people.