For the most part people are not capable of having internet connected IoT devices that don’t go to third party servers. You really think it’s a good idea to open up ports to shitty Chinese cameras inside your house and let them run as servers on the naked internet? Cameras that connect to third party servers need subscriptions to pay for the resources they consume.

Cameras that don’t need to be accessed over the internet are not the same market as internet connected cameras. For a thousand bucks or so you can get a few decent cameras and an NVR and have all the local camera viewing and recording you want. But most people don’t really need that.