If you think the useless appliances are bad, just take a look at more critical connected devices.
I needed some POE security cameras, found some foscam ones on the cheap. Plug them up, go to IP, “install our app”… was pleased to find it allowed a local account without the need for an email, but found that half of my network traffic was comprised of requests to their “ivyIOT AI detection”. I didnt measure what data was going through before sectioning them behind a firewall zone.
My fault for not having looked further into other brands, they were still a bargain and work without issue with my setup, but annoying