I mean why is it so difficult for such companies to understand the core thing: irrespective of whether the data related to our daily lives gets processed on their servers or ours, we DON'T want it stored beyond a few minutes at max.

Even if these folks are giving away this device for 100% free, I'll still not keep it inside my house.

Because storing, analyzing, and selling access to your data is massively profitable and they don’t care what the (not even vocal) privacy focused minority wants.